NEW YORK, September 10, 2008 (AFP) - Ailing investment bank Lehman Brothers announced plans Wednesday to sell off key assets to shore up its finances as it posted more hefty losses linked to the US subprime real estate crisis.

The beleaguered Wall Street firm, seen as in desperate need for a capital injection, lost an estimated 3.9 billion dollar in its fiscal third quarter amid fresh writedowns on mortgage assets.

The results, published a week ahead of schedule in view of a near-meltdown in Lehman shares, also noted plans to sharply reduce its exposure to the real estate sector and other steps to raise cash.

Lehman shares saw volatile trade Wednesday, losing 6.9 percent to 7.25 dollars. The shares had tumbled 44.95 percent Tuesday to end at 7.79 and have plunged nearly 90 percent since February.

The asset sales include a stake in Lehman's investment management unit as well as a chunk of its British real estate portfolio. The firm also said it would spin off its commercial real estate division.

'This is an extraordinary time for our industry, and one of the toughest periods in the firm's history,' chairman and chief executive Richard Fuld said.

'The strategic initiatives we have announced today reflect our determination to fundamentally reposition Lehman Brothers by dramatically reducing balance-sheet risk, reinforcing our focus on our client-facing businesses and returning the firm to profitability.'

Lehman said it would generate capital through the sale of a majority stake of around 55 percent in its investment management division.

The firm also said it was 'formally engaged with BlackRock Financial Management,' to sell an estimated 4.0 billion dollars of its British residential mortgage portfolio.

Another step announced was the spinoff of its commercial real estate portfolio worth some 25 billion to 30 billion dollars.

The new structure leaves Lehman with 'limited commercial real estate exposure,' in an effort to ease fears it could be hurt by a slump in commercial property expected following the collapse in the residential real estate market.

The moves came after a meltdown of shares of the white-shoe Wall Street investment bank as hopes faded for an injection of fresh capital.

Those hopes were dashed Wednesday as South Korea's state-run Korea Development Bank announced that it had abandoned negotiations about buying a stake in Lehman Brothers.

Lehman announced its moves in a bid to shore up confidence and avert the kind of meltdown of confidence that killed rival Bear Stearns earlier this year. But some analysts were unimpressed.

'Investors continue waiting for an actual buyer or business partner to emerge,' said Jeffrey Ham at Briefing.com.

Others were more skeptical.

'Lehman's strategic initiatives struck investors more as the intent to raise capital rather than actually getting the cash,' said Peter Cohan of Peter Cohan & Associates.

'Investors appear spooked by the failure to close any capital-raising deals.'

The results come after an unprecdented 2.8 million-dollar loss in the second quarter, the first loss since the investment firm went public in 1994.

Like other banking firms, Lehman suffered billions of dollars in writedowns and credit losses in the crisis triggered by the meltdown of the US high-risk subprime mortgage sector.

It has eliminated approximately 1,500 jobs since the beginning of the third quarter in an effort to contain costs.