Aug. 30 (Bloomberg) -- Research In Motion Ltd. rose to a record on the Nasdaq Stock Market amid speculation the maker of BlackBerry e-mail devices may be bought by Microsoft Corp., the world's largest software maker, traders said.

``We're hearing the same rumor everyone else is, the Microsoft and RIM rumor,'' said Steve Sachs, head of trading at Rydex Investments in Rockville, Maryland. ``I can't even count the number of times we've heard that over the last three years.''

Microsoft aims to sell software to as many mobile-phone makers as possible and therefore it wouldn't make sense to align itself closely with a single manufacturer, said Lawrence Harris, an analyst at Oppenheimer & Co. in New York. He rates Research In Motion ``neutral'' and doesn't own the stock.

Research In Motion shares gained $1.05, or 1.3 percent, to $82.87 at 4 p.m. New York time and earlier climbed as high as $85. Microsoft fell 14 cents to $28.45.

Courtney Flaherty, a spokeswoman for Waterloo, Ontario-based Research In Motion, wasn't available. Microsoft spokesman Bill Cox declined to comment.

``There's a rumor Microsoft is going to acquire some or part of RIM,'' said Greg Palmer, head of equity trading at Pacific Crest Securities Inc. in Portland, Oregon. ``It doesn't make sense because they've already got a handheld product.''

Bidders for Research In Motion would probably have to pay at least 50 percent more than the stock's price to persuade founders James Balsillie and Mike Lazaridis to sell, said Peter Misek, an analyst at Canaccord Capital Corp. in Toronto.

Microsoft making an offer for all of Research In Motion is ``incredibly unlikely'' and would be ``out of character,'' he added. Buying a small stake is more likely, Misek said.

Microsoft makes an operating system for hand-held computers. The software for more advanced wireless devices such as mobile phones allows users to check e-mail, listen to music and transmit photographs.

To contact the reporters on this story: Jeff Kearns in New York at jkearns3@bloomberg.net; Eric Martin in New York at emartin21@bloomberg.net.

Last Updated: August 30, 2007 16:36 EDT