By Natsuko Waki

LONDON (Reuters) - World stocks fell on Wednesday while safe-haven government bonds and the yen rose after U.S. investment bank Lehman Brothers LEH.N disappointed investors with a bigger-than-expected quarterly loss.

Lehman, a casualty of the credit crunch, posted a preliminary quarterly loss of $5.92 a share, compared with Reuters Estimates of a loss of $3.43.

The bank also said it would spin off its commercial real estate assets into a new, separate public company, adding it is examining all strategic alternatives.

Lehman's announcement offered the latest piece of negative news for risky assets. The market correction of the past 12 months has weighed on investor sentiment and threatened to kick major economies into recession.

"Overall, the deleveraging will continue, and if that's the case, more assets will have to be written down further and credits will remain tight. All that doesn't spell well for the stock market," said Lou Brien, market strategist at DRW Trading in Chicago.

The FTSEurofirst 300 index fell 1.4 percent while the MSCI main world equity index .MIWD00000PUS lost 0.7 percent, approaching last week's two-year low.

U.S. stock futures were down 0.4 percent, indicating a firmer open on Wall Street later.

Lehman shares erased early gains to trade lower in pre-market dealings, also coming under pressure after its talks to raise fresh capital from Korean Development Bank collapsed earlier.