In addition, the struggling bank said it has appointed Riccardo Banchetti and Christian Meissner co-chief executive officers of Europe and the Middle East and announced that Jeremy Isaacs will retire as chief executive officer for Europe, the Middle East and Asia-Pacific at the end of the year.

Lehman Chief Executive Officer Dick Fuld said in the statement that the appointments draw on the bank's "deep bench strength." The fourth-biggest US investment bank is under pressure to raise capital.

Mr Felder was previously head of global credit products and municipal finance, while Mr Lee was most recently head of capital markets for Asia. Both will join the bank's executive committee along with Mr Meissner and Mr Banchetti.

Mr Morton and Benoit Savoret, chief operating officer of Europe and the Middle East, have left the firm to pursue other interests, the bank said in its statement.

Lehman Brothers shares have dropped more than 75 per cent this year although its share price climbed nearly 7 per cent on Friday to close at $16.20, following news that private equity firms were looking to buy some of its assets.

The investment bank has already taken $7 billion in credit-related write-downs and losses since the start of the global credit crisis and it is expected to announce further losses when it releases its quarterly results.