On April 27, 2011, the Company entered into an Amended and Restated Revolving Credit and Security Agreement with PNC Bank, for itself and as agent for a group of lenders (Credit Facility). This Credit Facility replaced an existing facility that had a $97.5 million borrowing base and which matured on March 30, 2012 (Prior Facility). The Credit Facility, which matures April 27, 2016, provides for a borrowing base equal to $125 million, with a permitted increase of up to an additional $25 million for a maximum borrowing base of $150 million. Amounts outstanding under the Credit Facility bear interest, depending upon facility usage, at either (i) the higher of the Federal Funds Open Rate plus 50 to 100 basis points or PNC Bank's base commercial lending rate (4.0% at June 30, 2011) or (ii) LIBOR plus 225 to 275 basis points (2.7% at June 30, 2011). Interest on outstanding loans is due monthly for domestic rate loans and at the end of the relevant interest period for LIBOR loans. Depending upon our facility usage, we are assessed an unused line fee of 25 to 50 basis points on the available borrowing capacity. The available borrowing capacity was $60.0 million at June 30, 2011. There is a $10.0 million sublimit for letters of credit issued under the Credit Facility. We will incur a prepayment penalty if the Credit Facility is terminated prior to April 2014. As of June 30, 2011, we had a loan balance of $60.8 million under the Credit Facility, and an additional $4.2 million of the total capacity was utilized to support our letter of credit requirements.
On August 1, 2011, the accordion feature of the Credit Facility was exercised to add a new lender, on the same contractual terms, and increase the maximum capacity to $150 million.
In general, the Credit Facility is secured by substantially all of our assets. The forced liquidation value of our assets serving as collateral is determined at least annually by an independent appraisal, with adjustments for acquisitions and dispositions between appraisals. The Credit Facility contains affirmative and negative covenants and also provides for events of default typical for such an agreement. Among the affirmative covenants are requirements to maintain a specified tangible net worth. As of June 30, 2011, our actual tangible net worth was $193.3 million compared to the required minimum tangible net worth of $157.1 million. Among the negative covenants are restrictions on major corporate transactions, incurrence of indebtedness and amendments to our organizational documents. Events of default would include a change in control and any change in our operations or condition which has a material adverse effect. As of June 30, 2011, we were in compliance with all of our covenants.
The Prior Facility's outstanding amounts bore interest, depending upon facility usage, at either (i) the higher of the Federal Funds Open Rate plus 75 to 125 basis points or PNC Bank's base commercial lending or (ii) LIBOR plus 250 to 300 basis points. At December 31, 2010, we had a loan balance of $30.0 million of which $4.3 million of the total capacity had been utilized to support our letter of credit requirement; further, the available borrowing capacity was $63.2 million at December 31, 2010. The Prior Facility was also secured, in general, by substantially all of our assets and contained normal and customary representations and warranties similar to the Credit Facility, although the Prior Facility required a minimum fixed charge coverage ratio in addition to the tangible net worth. As of December 31, 2010, our actual tangible net worth was $200.5 million compared to the required minimum tangible net worth of $66.8 million, and our actual fixed charge coverage ratio of 13.2 exceeded the required 1.1 fixed charge coverage ratio. Among the negative covenants were restrictions on major corporate transactions, incurrence of indebtedness and amendments to our organizational documents. At December 31, 2010, we were in compliance with all of our covenants.
Our credit facilities primarily have been used to pay for rig acquisitions and for working capital requirements. The Credit Facility may also be used by the Company, subject to certain conditions, to repurchase its common stock and/or pay a cash dividend.
In addition, the Company has entered into various equipment-specific financing agreements with various third-party financing institutions. The terms of these agreements had initial terms ranging from 24 to 48 months. As of June 30, 2011 and December 31, 2010, the total outstanding balance under these arrangements was approximately $56,000 and $173,000, respectively, and is classified, according to payment date, in current portion of notes payable for equipment and long-term notes payable for equipment in the accompanying balance sheets. At June 30, 2011, the stated interest rate on these borrowings ranged from zero percent to 3.8%.