Microsoft Corp., the world's largest software maker, announced a new $40 billion stock buyback plan and increased its dividend 22 percent, seeking to reward shareholders as the company undergoes a change in strategy and leadership.

The repurchase program, which has no expiration date, replaces another $40 billion buyback plan that was due to lapse at the end of this month, Microsoft said today in a statement. The company's quarterly dividend will rise to 28 cents a share, payable on Dec. 12 to shareholders of record as of Nov. 21.

The move is a step in the right direction for investors, though the open-ended schedule for the new buyback plan raises questions, said Matthew Hedberg, an analyst with RBC Capital Markets in Minneapolis. The company has come under pressure from activist investor ValueAct Holdings LP, which pushed Microsoft to return more money to shareholders, according to a person with knowledge of the matter.