Activist investor Carl Icahn responded to Motorola’s announcement to split the company into two yesterday by publishing a letter to the struggling handset manufacturer’s board. Icahn, who has argued for the split, called the announcement “much delayed and long overdue” as well as a “step in the right direction.”

Icahn, known for outspoken responses to company’s performance and management issues, went on to write: “I continue to have concerns about the speed and manner in which a new management team is selected for the Mobile Devices business and the separation transaction is consummated. Time is of the essence and decisive action is required to reposition the Mobile Devices business for success as an independent company.”

Icahn questioned why Motorola was waiting until 2009 to split the company and expressed concerns that the company might back out of its plan to divide into two.

Icahn and Motorola are currently involved in the second public spat in a year. Icahn recently refused Motorola’s offer of two out of his four board nominations. Icahn, in his letter about the separation, said the company misrepresented discussions about his board nominees and continued to insist that his nominee Keith Meister be given a seat. Meister is head of Icahn’s investment fund.