Billionaire investor Carl Icahn has raised his stake in U.S. cell phone maker Motorola to 6.3 percent from 5 percent, according to a regulatory filing on Wednesday.
The activist investor, who heads Icahn Enterprises, has been pressuring Motorola to break up, saying it would create more value for shareholders. On Feb. 1, Icahn nominated four executives for election to Motorola's board.
According to the filing with the U.S. Securities and Exchange Commission, Icahn's entities now own 142.36 million shares of Motorola, purchased for $2.06 billion, including commissions.
Motorola said at the end of January it was looking at options such as a potential separation of its loss-making mobile devices division.
Its shares rose 1.8 percent to $10.20 in extended trading, from their close of $10.02 on the New York Stock Exchange.