OSLO, Oct 16 (Reuters) - The Norwegian police economic crimes unit said it had charged Microsoft-owned search technology firm Fast Search & Transfer with accounting fraud on Thursday.

“We are raiding Fast’s offices now to secure evidence,” police attorney Baard Thorsen said. “The charge is for accounting fraud.”

Fast was acquired by Microsoft MSFT.O for $1.2 billion in February.

“The charge regards accounts from before Microsoft came in,” Thorsen said. “We think Fast recognised revenues that there is no basis for.”

Fast was not immediately available for comment.

Norway’s financial watchdog said in May it had reported possible violation of accounting rules by Fast to the economic crimes unit.

In June the watchdog said it would also probe the auditor of Fast, Deloitte & Touche DLTE.UL, for suspected irregularities in the computer group's accounts.

Fast is the world's second largest provider of enterprise search software that allows companies to comb internal corporate documents, data and other information, a market also targeted by Google GOOG.O.

Before Microsoft’s buyout, Fast stock had tumbled after the company said in mid 2007 it would no longer recognise revenues from memorandums of understanding, and instead book revenue only from final deals.

The police and Norwegian Ministry of Justice are among Fast’s customers in Norway.

(Editing by Elaine Hardcastle)

((richard.solem@reuters.com; +47 22 93 69 77; rm://richard solem.reuters.com@reuters.no)) Keywords: MICROSOFT/FAST