Microsoft has offered to buy Yahoo for around $44.6 billion in cash and shares, to better compete with Google in the market for online services.

Buzzblog: Microsoft offers $44.6B for Yahoo

On a conference call Friday, Microsoft CEO Steve Ballmer called a combination of Microsoft and Yahoo a more "credible" alternative to Google in the online advertising and services market.

"By combining the assets of Microsoft and Yahoo we can offer a more competitive choice for consumers, advertisers and publishers," he said.

It was Yahoo's board that first approached Microsoft, in February 2007, Microsoft said.

Yahoo, in a statement, said its board will carefully evaluate Microsoft's proposal, which it described as unsolicited.

Microsoft expects the market for online advertising to almost double in size over the next three years, from $40 billion in 2007 to $80 billion by 2010. A merger will allow it to realize economies of scale and reduce capital costs as it addresses this market, it said.

"The combination of these two great teams would enable us to jointly deliver a broad range of new experiences to our customers that neither of us would have achieved on our own," said Ray Ozzie, chief software architect at Microsoft, in a statement.

Microsoft expects to cut costs by $1 billion a year by realizing synergies with Yahoo in four areas: obtaining economies of scale as its audience increases; combining its research and development efforts with Yahoo's to innovate faster; eliminating operational redundancy to cut costs, and pooling expertise to innovate in video and mobile.

The companies will work together to develop the merger plan, Microsoft said.

It intends to pay key Yahoo engineers and other staff to stay following the merger.

The offer represents a 62% premium over Yahoo's closing price on Thursday. Microsoft expects to receive all necessary approvals in the second half of this year.

Despite the potential for short-term gain, Yahoo, in its statement, said its goal will be to maximize long-term value for shareholders.

At this premium, even if Yahoo's top managers were opposed to the acquisition, Yahoo's board of directors has an obligation to consider the offer on behalf of shareholders, said industry analyst Greg Sterling from Sterling Market Intelligence.

The IDG News Service is a Network World affiliate.