American Capital Ltd. (Nasdaq: ACAS) has closed a private equity fund with $1.1 billion in commitments, during the best fundraising climate in years. 

American Capital Equity III LP's investors include Coller Capital, Goldman Sachs Asset Management and StepStone Group, plus sovereign wealth funds, state retirement and pension systems, high net worth family offices and superannuation funds and foundations. The fund has a total of 39 limited partners.

The fund has agreed to buy a portfolio of equity and equity-related investments from American Capital valued at $640 million. Another $445 million from the fund will be used to make new control equity and other investments.

Bethesda, Maryland-based American Capital, led by CEO Malon Wilkus (pictured), is a publicly-traded private equity firm and asset manager. The company originates, underwrites and manages investments in middle-market private equity, leveraged finance, real estate, energy, infrastructure and structured products. The group manages $19 billion in assets. American Capital makes investments between $10 million and $750 million. The firm's investments include Cambridge Major Laboratories, Service Experts LLC and ASAP Industries LLC.

Kirkland & Ellis LLP provided legal advice to American Capital. 

Other private equity firms have also been closing funds. Earlier in September, CCMP Capital closed a $3.6 billion fund. Before that, also in September, the Carlyle Group closed a $3.9 billion fund.