Calpers, which is the biggest U.S. public pension fund and is also an investor in many of Carlyle's funds, acquired a 5.5 percent stake in Carlyle in 2001 for $175 million. That later got diluted to 4 percent.
In May 2012, Thomson Reuters Buyouts Magazine reported Calpers had until then received $225.2 million in carried interest, fees, and distributions from its Carlyle stake, based on a California Public Records Act request.
Also accounting for Carlyle's distributions as a public firm since May 2012, this would mean Calpers stands to make close to 3.5 times its money on its Carlyle stake investment over a period of 12 years, calculations by Reuters show.
The sale of the stake in Carlyle, disclosed in a regulatory filing on Monday, comes one month after Calpers moved to sell a quarter of its 8 percent stake in Apollo.
(Watch: Foreclosure TrialPits Calpers Against Wall Street)
Calpers joined Abu Dhabi Investment Authority and two of Apollo's founders in selling some of its shares in New York-based Apollo. It raised $187.5 million by cutting its stake in Apollo to 6 percent from 8 percent.
Founded in 1987 by David Rubenstein, William Conway, and Daniel D'Aniello, Carlyle had total assets under management of $176.3 billion as of the end of March, including in private equity, corporate credit, and hedge funds.
Citigroup, Credit Suisse, and JPMorgan Chase will serve as the book-running managers for Calpers' offering.
(See: Calpers to Battle Zombie Boards)
Calpers also has a stake in Silver Lake, a technology sector-focused private-equity firm which, unlike Carlyle and Apollo, has not gone public. Calpers acquired the 9.9 percent share in 2008.
Calpers had $4 billion—equivalent to 10 percent of its private-equity program—invested with Carlyle as of the end of the end of March, ranking the Washington, D.C.-based firm as the second-largest exposure in Calpers' private equity portfolio. It had $4.3 billion invested with Apollo and $1.1 billion invested with Silver Lake.