Lehman Brothers, facing the biggest losses in its 158-year history, announced plans to sell a majority stake in its prized asset management business in an effort to keep the firm afloat. But the sale will not include Lehman’s minority stakes in hedge funds D.E. Shaw Group and Ospraie Asset Management.

Bids for the 55% stake in Lehman’s asset management unit, which includes Neuberger Berman, are due this weekend. Among the finalists are some of the biggest names in private equity, including Bain Capital, Hellman & Friedman and Kohlberg Kravis Roberts. Sifting through the bids is expected to take several weeks.

The asset management sale is just one piece of a major restructuring at Lehman, which is battling to avoid becoming the next Bear Stearns. The New York investment bank plans to slash its operations and move $30 billion of increasingly toxic mortgage and real estate investments into a separate bank, owned by Lehman shareholders, in the hopes that those assets will eventually recover, but won’t sink the firm in the meantime.

Parties interested in the hedge fund stakes may not be out of luck yet: Lehman may still sell what’s left of itself after the restructuring.