In Thursday's letter, however, Motorola said: "Icahn has not given us the name of 'another large shareholder' who could serve in lieu of him. In fact, Carl Icahn has only suggested that an employee from his hedge fund staff, such as 34 year-old Keith Meister, and an additional independent director to be identified, could be added to the board in lieu of himself."
Motorola also questioned his motives for seeking a board seat at Monday's annual shareholder meeting.
“We therefore do not believe that Carl Icahn is sincere when he says that he is committed to serving on Motorola’s Board,” the company said. “We question – as (shareholders) should – whether Carl Icahn will act in the best interests of all Motorola stockholders, or just in the best interest of Carl Icahn.”
Since January, Icahn and his affiliates have bought 2.9% of Motorola's stock, a stake worth nearly $1.3 billion.
Motorola has maintained that Icahn isn't qualified for its board and has too many other involvements.
Last month, Motorola posted its first quarterly loss since 2004 amid dismal sales in its largest segment, mobile devices.
In Wednesday's interview, Icahn lashed back at Motorola, saying "earnings were so bad that the company had no measure of what they were doing." "
"We're one of the largest shareholders," Icahn said. "We don't think it's well-managed. We don't believe the board has done a good job. Today a lot of things came out --obfuscated the situation so much, that I felt I should come on."