Exhibit 99.4

TO: ALL TRANSATLANTIC EMPLOYEES

FROM: BOB ORLICH

DATE: NOVEMBER 21, 2011

We have some important and exciting news to share with you today. Transatlantic today announced that it has signed an agreement under which Transatlantic will combine with Alleghany Corporation in a transaction valued at approximately $3.4 billion. Attached to this email you will find a copy of today’s press release detailing today’s announcement.

Alleghany Corporation is a leading U.S. specialty insurance platform with a superior investment track record. Through its subsidiaries, Alleghany engages in the property and casualty, and surety insurance business in the U.S. You can find out more about Alleghany at www.alleghany.com.

Our board’s decision to embark on this transaction concludes a lengthy but very thorough process. In the end, our Board is convinced that Alleghany offers our stockholders compelling value and growth potential that puts tremendous emphasis on the strength of our franchise and provides clarity and stability in the midst of the January 1 renewal season.

The combined company will be an industry leader with pro forma net premiums written of $4.7 billion over the preceding 12 months, greater diversification by product and geography, total stockholders’ equity of $5.9 billion, and total capital of $7.2 billion as of September 30, 2011. Transatlantic will operate as an independent subsidiary of Alleghany, with Mike leading the franchise as CEO and I will continue to serve as a director. What this means is that Transatlantic will continue to operate as it always has. We will retain our brand name, and under Alleghany’s ownership structure, will continue to invest in and grow the business.

As an independent subsidiary of Alleghany, Transatlantic will not only enhance its long-term value creation potential but will also preserve our franchise that we have worked so hard to build over the last 30-plus years. Importantly, it is also expected that Transatlantic will maintain its current ratings of “A+” from Standard & Poor’s and “A” from A.M. Best. Both companies are complementary with virtually no overlap in their underwriting operations and highly compatible cultures, which we believe will make integration seamless and efficient. We anticipate no changes to your day-to-day responsibilities as a result of today’s announcement.

As always, we are committed to keeping you informed throughout this process. If you have additional questions in the meantime, please feel free to reach out to Gary Schwartz, EVP & General Counsel at (212) 365-2050 or via email at gschwartz@transre.com. Further, as this situation is likely to generate media interest, it is important that we continue to speak with one voice. If you receive any questions from the media or any other external parties regarding this matter, please forward them to Tom Cholnoky at (212) 365-2292.

Thank you for your ongoing focus and continued commitment to Transatlantic — I wish all of you a safe and happy Thanksgiving. I certainly hope you share in our excitement as we head into this next chapter of our Company’s history.

Sincerely,

Bob

Chief Executive Officer

Cautionary Note Regarding Forward-Looking Statements

In addition to historical information, this document contains forward-looking statements within the meaning of Section 27A of the U.S. Securities Act of 1933, as amended, and Section 21E of the U.S. Securities Exchange Act of 1934, as amended. These forward-looking statements, which are based on current expectations, estimates and projections about the industry and markets in which Alleghany and Transatlantic operate and beliefs of and assumptions made by Alleghany management and Transatlantic management, involve uncertainties that could significantly affect the financial results of Alleghany or Transatlantic or the combined company. Words such as “expects,” “anticipates,” “intends,” “plans,” “believes,” “seeks,” “estimates,” variations of such words and similar expressions are intended to identify such forward-looking statements, which generally are not historical in nature. Such forward-looking statements include, but are not limited to, statements about the benefits of the transaction involving Alleghany and Transatlantic, including future financial and operating results, the combined company’s plans, objectives, expectations and intentions. All statements that address operating performance, events or developments that we expect or anticipate will occur in the future — including statements relating to creating value for stockholders, increasing capital and investments, achieving diversification and returns with minimal integration risk, maintaining financial ratings, integrating our companies, providing stockholders with a more attractive currency, and the expected timetable for completing the proposed transaction — are forward-looking statements. These statements are not guarantees of future performance and involve certain risks, uncertainties and assumptions that are difficult to predict. Although we believe the expectations reflected in any forward-looking statements are based on reasonable assumptions, we can give no assurance that our expectations will be attained and therefore, actual outcomes and results may differ materially from what is expressed or forecasted in such forward-looking statements. For example, these forward-looking statements could be effected by factors including, without limitation, risks associated with the ability to consummate the merger and the timing of the closing of the merger; the ability to successfully integrate the our operations and employees; the ability to realize anticipated benefits and synergies of the transaction; the potential impact of announcement of the transaction or consummation of the transaction on relationships, including with employees, credit rating agencies, customers and competitors; the ability to retain key personnel; the ability to achieve targets for investment returns, revenues, and book value per share; risks that the unsolicited exchange offer and consent solicitation commenced by Validus Holdings, Ltd. disrupts current plans and operation; changes in financial markets, interest rates and foreign currency exchange rates; greater frequency or severity of unpredictable catastrophic events; negative rating agency actions; the adequacy of each party’s loss reserves; the cyclical nature of the property and casualty insurance industry; and those additional risks and factors discussed in reports filed with the Securities and Exchange Commission (“SEC”) by Alleghany and Transatlantic from time to time, including those discussed under the heading “Risk Factors” in their respective most recently filed reports on Form 10-K and 10-Q. Neither Alleghany nor Transatlantic undertakes any duty to update any forward-looking statements contained in this communication.

Additional Information about the Proposed Transaction and Where to Find It

In connection with the proposed transaction, Alleghany intends to file with the SEC a registration statement on Form S-4 that will include a joint proxy statement of Alleghany and Transatlantic that also constitutes a prospectus of Alleghany. Transatlantic and Alleghany also plan to file other relevant documents with the SEC regarding the proposed transaction. INVESTORS ARE URGED TO READ THE JOINT PROXY STATEMENT/PROSPECTUS AND OTHER RELEVANT DOCUMENTS FILED WITH THE SEC IF AND WHEN THEY BECOME AVAILABLE, BECAUSE THEY WILL CONTAIN IMPORTANT INFORMATION. You may obtain a free copy of the joint proxy statement/prospectus (if and when it becomes available) and other relevant documents filed by

Alleghany and Transatlantic with the SEC at the SEC’s website at www.sec.gov. You may also obtain these documents by contacting Transatlantic’s Investor Relations department at Transatlantic Holdings, Inc., 80 Pine Street, New York, New York 10005, or via e-mail at investor_relations@transre.com; or by contacting Alleghany at Alleghany Corporation, 7 Times Square Tower, New York, New York 10036.

Alleghany and Transatlantic and their respective directors and executive officers and other members of management and employees may be deemed to be participants in the solicitation of proxies in respect of the proposed transaction. Information about Alleghany’s directors and executive officers is available in Alleghany’s proxy statement dated March 17, 2011 for its 2011 Annual Meeting of Stockholders. Information about Transatlantic’s directors and executive officers is available in Transatlantic’s proxy statement dated April 8, 2011 for its 2011 Annual Meeting of Stockholders. Other information regarding the participants in the proxy solicitation and a description of their direct and indirect interests, by security holdings or otherwise, will be contained in the joint proxy statement/prospectus and other relevant materials to be filed with the SEC regarding the merger when they become available. Investors should read the joint proxy statement/prospectus carefully when it becomes available before making any voting or investment decisions. You may obtain free copies of these documents from Alleghany or Transatlantic using the sources indicated above.

This document shall not constitute an offer to sell or the solicitation of an offer to buy any securities, nor shall there be any sale of securities in any jurisdiction in which such offer, solicitation or sale would be unlawful prior to registration or qualification under the securities laws of any such jurisdiction. No offering of securities shall be made except by means of a prospectus meeting the requirements of Section 10 of the U.S. Securities Act of 1933, as amended.

Additional Information about the Validus Exchange Offer

     This communication is neither an offer to purchase nor the solicitation of an offer to sell any securities. In response to the exchange offer commenced by Validus Holdings, Ltd. (“Validus”), Transatlantic has filed a Solicitation/Recommendation Statement on Schedule 14D-9 with the SEC. Investors and security holders are urged to read the Solicitation/Recommendation Statement on Schedule 14D-9 because it contains important information about the Validus exchange offer. All documents, when filed, will be available free of charge at the SEC’s website (www.sec.gov). You may also obtain these documents by contacting Transatlantic’s Investor Relations department at Transatlantic Holdings, Inc., 80 Pine Street, New York, New York 10005, or via e-mail at investor_relations@transre.com.

Additional Information about the Validus Consent Solicitation

     On November 3, 2011, Validus filed an amended preliminary consent solicitation statement with the SEC relating to Validus’s proposals to, among other things, remove all of of Transatlantic’s directors and nominate three new directors to the Transatlantic board of directors. Transatlantic has filed with the SEC a preliminary consent revocation statement on Schedule 14A (the “Preliminary Revocation Statement”) in connection with Validus’s solicitation of written consents. Investors and security holders are urged to read the Preliminary Revocation Statement and Transatlantic’s definitive consent revocation statement, when it is available, because they contain important information. Investors can get the Preliminary Revocation Statement, the definitive revocation statement, when it is available, and any other relevant documents for free at the SEC’s website (www.sec.gov). You may also obtain these documents for free by contacting Transatlantic’s Investor Relations department at Transatlantic Holdings, Inc., 80 Pine Street, New York, New York 10005, or via e-mail at investor_relations@transre.com.

     Transatlantic, its directors and executive officers may be deemed to be participants in a solicitation of Transatlantic’s stockholders in connection with the Validus consent solicitation. Information about Transatlantic’s directors and executive officers, and a description of their direct or indirect interests, by security holdings or otherwise, is available in Transatlantic’s Preliminary Revocation Statement, which was filed with the SEC on September 20, 2011.