The Harvard Management Company—the group charged with investing the University’s $36.9 billion endowment—is planning to unload $1.5 billion of its riskiest assets, The Wall Street Journal reported yesterday.

The Journal’s article followed similar reports from the trade publication Private Equity Week, which said the company would sell $1 billion of its private equity portfolio.

A $1.5 billion sale of its private equity holdings—nearly a third of Harvard’s investments in that sector—would mark one of the largest-ever sales of a private-equity portfolio, The Journal article said.

As of June 30, HMC’s planned allocation to private equity for 2009 was up to 13 percent of the University’s endowment, or just under $4.8 billion.

University spokesman John D. Longbrake declined to confirm the sale when asked about the Private Equity Week report last week, citing a standing Harvard policy not to “discuss investment strategies or individual investments.”

Several Boston-area hedge funds that received substantial initial investments from Harvard—including ex-HMC chief Jack R. Meyer’s Convexity Capital Management—also declined to comment at the time on any action HMC may be taking to sell investments it has with them.

Private equity has traditionally been one of the best-performing asset classes for Harvard’s endowment, earning an annualized return of 28.5 percent over the past 10 years and posting a 9.3 percent gain in fiscal year 2008, beating the endowment’s overall return of 8.6 percent.

Private equity investments have taken a hit from current economic distress that has crippled investors’ access to capital—a key driver of gains in that sector.

Harvard would not be alone if it did unload much of its private-equity portfolio, according to The Journal.

The newspaper reported that the nation’s largest public pension fund—the $189.6 billion California Public Employees Retirement System–has requested that private-equity firms “ease off” of demands for capital that the fund had previously promised.