Microsoft made a $1.2 billion offer to buy Norwegian Web search software company Fast Search & Transfer in a deal that would help the world's largest software maker expand into the market for business-oriented search.

Fast designs real-time data search and filtering software and helps filter internal corporate sites. Its clients include Dell and IBM, and it has been viewed by industry analysts as a takeover candidate.

"The problem businesses have around the world is they generate lots of files and they don't know where they put them," said Kim Caughey, senior equity analyst at Fort Pitt Capital, which holds about 203,000 Microsoft shares.

"Microsoft has had desktop search for a while but it really does need a more corporate approach to tracking and storing," she said.

Fast said its board had unanimously recommended that shareholders accept the Microsoft offer, which represents a 42 percent premium to Fast's closing share price on January 4, the last day on which it traded.

The offer values the fully diluted equity of Fast at 6.6 billion Norwegian crowns, or about $1.2 billion.

Shareholders with 37 percent of Fast's stock, including its two biggest institutional investors -- Norway's Orkla and Hermes Focus Asset Management Europe -- have agreed to accept the offer, Fast and Microsoft said.

Fast shares, which were suspended all day on Monday, jumped to the bid level of 19 crowns per share and then eased off slightly to 18.80 crowns.

The news pushed shares of Autonomy, a British rival of Fast, up nearly 10 percent. Microsoft shares fell 30 cents to $34.31 on the Nasdaq.

Analysts expect Microsoft's bid to succeed.

"The bid is fair. There can always be another (rival offer), but I believe Microsoft will get it for 19 crowns a share," said analyst Erik Hjulstroem at Kaupthing Bank.

Standard & Poor's analyst Matthias Eriksson said, "I don't think there will be a competing bid. The premium is too high, so I think people will be glad to get 19 crowns."

The deal is subject to regulatory approval and acceptance from shareholders with more than 90 percent of Fast's shares, Fast said.

Microsoft expects the transaction to be completed in the second quarter of 2008.

"Enterprise search is becoming an indispensable tool to businesses of all sizes, helping people to find, use and share critical business information quickly," said Jeff Raikes, head of the Microsoft Business division.

The deal would spread Fast's search technologies more widely around the world, Fast Chief Executive John Lervik said. Fast posted a third-quarter loss of more than $100 million on revenue of nearly $36 million.

Goldman Sachs is acting as financial adviser to Microsoft, and Merrill Lynch is advising Fast.