Securities and Exchange Commission and Federal Reserve officials were warned by a leading Wall Street rival that Lehman Brothers was incorrectly calculating a key measure of its financial health months before its collapse in 2008, people familiar with the matter say.

Former Merrill Lynch officials said they contacted regulators about the way Lehman measured its liquidity position for competitive reasons. The Merrill officials said they were coming under pressure from their trading partners and investors, who feared that Merrill was less liquid then Lehman.

The warnings take on a special significance after last week's report by Anton Valukas, the Lehman bankruptcy court examiner, who found that Lehman had used bank financing tools to flatter its balance sheet before its September 2008 collapse.