Motorola, the second largest mobile phone manufacturer, urged shareholders on Friday not to elect Carl Icahn, the billionaire Wall Street investor, to its board.

The plea, which comes as Motorola prepares for its annual meeting due to take place on May 7, came in a letter to shareholders which reiterated its criticism of Mr Icahn and his proxy battle.

The letter notes that Motorola’s board is, “unanimous” in its opposition to Mr Icahn. “We respect and value Carl Icahn’s role as a stockholder,” the letter stated, “In our view, however, he does not add to the strength of your Board.”

Mr Icahn, who has built up a 2.9 per cent stake in Motorola since mid January, has accused Motorola’s board of not acting quickly enough to head off problems in the company’s core mobile phone unit which saw margins plunge as after it cut prices in an effort to boost market share.

Last week Motorola, which has acknowledged that it made mistakes, announced a $181m loss in the first quarter.