Architect of Unsuccessful Yahoo Bid Leaves Microsoft

The architect of Microsoft's effort to buy Yahoo is leaving his job, in an unexpected move that raises questions about the software giant's continued pursuit of the Internet company, the San Jose Mercury News reported on Thursday.

Kevin Johnson, a longtime lieutenant of Microsoft Chief Executive Steve Ballmer, reportedly is taking a top job at Juniper Networks based in Sunnyvale, Silicon Valley, the paper reported.

Analysts said the move shows that Johnson -- or his notoriously demanding boss -- had become frustrated with Microsoft's failure to build an online business capable of challenging Internet giant Google by buying established Web companies.

Yahoo and Microsoft are the second- and third-ranked companies, respectively, in the lucrative search advertising market that is dominated by Google.

Johnson, who joined Microsoft from IBM in 1992, was president of Microsoft's platforms and services division, the largest of the company's three major units. He was also responsible for the company's flagship Windows software and related products.

It was Johnson who came up with a plan for expanding the business by buying other companies. But the bid in the spring to buy Yahoo turned into an epic and so far unsuccessful struggle, when Yahoo Chief Executive Jerry Yang balked at an initial offer and the two companies failed in subsequent efforts to reach an agreement.