Lehman Brothers Holdings Inc. bailed out three of its struggling investment funds and bought distressed assets from others for $1.8 billion, Wall Street bank said in a regulatory filing.

The bailout added $1 billion in assets to the company's balance sheet. It also bought about $800 million in deteriorated assets from other funds, according the Lehman's filing with the Securities and Exchange Commission on Wednesday.

The company did not specify exactly what the assets were, however the current credit crisis has involved losses on various types of risky debt securities which have fallen sharply in price.

Due to market disruptions that occurred in the second half of the 2007 fiscal year and further deterioration in the 2008 quarter, certain investments held by the funds were either downgraded by rating agencies and/or experienced a decline in fair value, the company stated.

The bank said it was not required to buy the assets. However not doing so would have led to the funds' failure, Lehman said.