As of December 31, 2012, the weighted average grade of the investments in our portfolio at fair value was 3.1. Also, as of December 31, 2012, loans on non-accrual status represented 2.3% of total investments at amortized cost (or 0.6% at fair value).
LIQUIDITY AND CAPITAL RESOURCES
As of December 31, 2012, Ares Capital had $269.0 million in cash and cash equivalents and $2.3 billion in aggregate principal amount of outstanding debt ($2.2 billion in carrying value). Subject to leverage and borrowing base restrictions, Ares Capital had approximately $1.6 billion available for additional borrowings under its existing credit facilities as of December 31, 2012.
In October 2012, we issued an additional $7.5 million in aggregate principal amount of our 5.875% senior unsecured notes due October 1, 2012 (the “October 2022 Notes”). The additional notes were issued pursuant to the partial exercise of an over-allotment option that we granted to the underwriters in September 2012 in connection with the October 2022 Notes offering, bringing the total aggregate principal amount of the October 2022 Notes to $182.5 million.
In addition, in the fourth quarter of 2012, we issued $270.0 million aggregate principal amount of unsecured convertible senior notes that mature on January 15, 2018 (the “2018 Convertible Notes”), unless previously converted or repurchased in accordance with their terms. We do not have the right to redeem the 2018 Convertible Notes prior to maturity. The 2018 Convertible Notes bear interest at a rate of 4.75% per year, payable semi-annually commencing on July 15, 2013. In certain circumstances, the 2018 Convertible Notes will be convertible into cash, shares of Ares Capital’s common stock or a combination of cash and shares of our common stock, at our election, at an initial conversion rate of 50.3290 shares of common stock per one thousand dollar principal amount of the 2018 Convertible Notes, which was equivalent to an initial conversion price of approximately $19.87 per share of our common stock, subject to customary anti-dilution adjustments. The initial conversion price of the 2018 Convertible Notes was approximately 17.5% above the $16.91 per share closing price of our common stock on October 3, 2012.