The real estate investment manager who led the California Public Employees' Retirement System, the nation's largest pension fund, into a money-losing land venture has resigned as an adviser to the fund, according to news reports.

Victor MacFarlane, chairman and chief executive of MacFarlane Partners, has terminated his relationship with the $200 billion pension fund, the Wall Street Journal reported on Saturday.

A spokeswoman for MacFarlane said his resignation was voluntary and that he would continue advising Calpers through the end of the year, the Journal reported.

MacFarlane's resignation was first reported by Reit Zone Publications.

Representatives for MacFarlane Partners and Calpers could not be reached to confirm the reports on Saturday afternoon.

MacFarlane Partners Inc is a real estate investment management firm in San Francisco that manages $10 billion in assets for some of the world's largest pension plans and institutions, according to its website.

The firm came under fire for a $970 million investment it managed for Calpers into LandSource Communities Development, the Journal said.

LandSource filed for bankruptcy in 2008, about 18 months after Calpers had bought into the 15,000-acre (6100-hectare) tract outside Los Angeles, Calpers said in a 2008 press release.

Calpers had invested in the development through its investment partner, MW Housing Partners, which was jointly managed by MacFarlane Housing and Weyerhaeuser Realty Investors, the release said.

MW Housing held a 68 percent interest in LandSource, whose holdings were hit hard by the California real estate bust, it said.

The separation comes as Calpers examines its relationships with private equity firm Apollo Global Management and other outside money managers.

Calpers said earlier this month that its probe centers on around $50 million in payments that outside managers made over a five-year period to ARVCO Financial Ventures LLC, a firm headed by former Calpers board member Al Villalobos, to win the pension fund's business.