Yahoo will test displaying Google search ads in a small number of its search engine queries, a move likely to be interpreted as the latest in a series of Yahoo maneuvers to resist Microsoft's acquisition attempt.

The test, expected to last up to two weeks and be limited to up to 3 percent of Yahoo search queries in the U.S., is specifically for Google's AdSense for Search service. In other words, Yahoo would be acting as one of the Web publishers that carry pay-per-click text ads from Google. The ads will appear only in Yahoo.com.

"This would make the market far less competitive, in sharp contrast to our own proposal to acquire Yahoo. We will assess closely all of our options," said Brad Smith, Microsoft's general counsel, in a statement.