The Parkmerced apartment complex, reportedly sold to a New York firm, also is the subject of proposed changes to planning regulations including height limits. The San Francisco Planning Commission is scheduled to consider starting the process of changing those rules on Oct. 21.

Fortress Investment Group LLC has bought an interest of about 75 percent in the massive Parkmerced housing complex on San Francisco’s west side, according to the Wall Street Journal. The deal pegged the value of the 3,221-unit complex at approximately $750 million, the Journal reported.

The acquisition leaves investment firm Rockpoint Group LLC, previously the majority owner of the World War II-era complex, with a minority stake, and extends the maturity of a $550 million mortgage that was coming due this month to February 2011, according to a Barclays Capital report on the deal. It isn’t clear how much Fortress paid. …

Some of the property’s potential upside comes from space for future development where some 6,000 new units can be built.

The deal comes just before the San Francisco Planning Commission is to consider starting a process of changing the city’s Planning Code and General Plan, and creating the “Parkmerced Special Use District.” The 590-page report prepared for Thursday’s special meeting of the commission details proposed changes to the limits on the height and bulk of new buildings that could be built in the new district surrounding Parkmerced. The proposed changes also would allow for the demolition and replacement of 1,538 rent-controlled housing units.

The proposed Parkmerced Special Use District would entail creating specific use categories including residential, mixed-use, school, community and open-space districts. It would regulate parking, car sharing and bike parking, and would establish a design review process for the future development of Parkmerced.

In addition to any approvals required by the Planning Department and the Planning Commission, the Board of Supervisors would have to approve the development agreement that would be needed for new building plans at Parkmerced to move ahead.

The commission is scheduled to assemble at 5 p.m. in a special City Hall meeting in Room 400.