Microsoft Corp. Chief Executive Officer Steve Ballmer plans to extend a management shake-up aimed at adding senior product executives with an engineering background, two people with knowledge of the decision said.

Changes may be announced this month, said one of the people, who declined to be named because the plans are private. Last month, Ballmer pushed out server division president and 23- year company veteran Bob Muglia, saying the company needed new leadership that could focus on areas such as cloud software.

The move would expand on an effort to promote managers who have engineering skills and experience executing product plans — a bid to catch up with rivals such as Apple Inc. and Google Inc. in Web services, smartphones and tablet computers. The overhaul also may quell criticism from the board and investors that Microsoft is falling behind in some markets. Four top executives have left the company since May.

“You see the engineering team ascending because Steve is realizing that there is a need to execute on a vision and in order to do that you have to actually understand how software is built,” said Wes Miller, an analyst at the Kirkland, Washington-based research firm Directions on Microsoft. “It’s a whole other thing to be able to say, ‘I’ve been at Microsoft, I understand software, and what you are saying will or will not work.’”