General Motors Corp. wants to borrow about $500 million from one or both of Detroit's pension funds to refinance the Renaissance Center, the automaker's iconic world headquarters, in a move that could pump cash into the financially strapped company's coffers.

GM officials are scheduled to make a preliminary investment pitch Thursday to the city's Police & Fire Retirement System and are trying to schedule a meeting with the pension fund representing general city employees, The Detroit News has learned.

If a deal cannot be reached, GM will consider selling the landmark and leasing space within the RenCen, John Blanchard, GM's executive director of worldwide real estate, said Monday.