DETROIT (Reuters) -- General Motors Corp. and Boeing Co. declined to comment Wednesday on a report that the aircraft manufacturer plans to buy Hughes Electronics Corp.'s satellite-manufacturing business from the world's largest automaker.

"We don't comment on speculation and rumor and that's what this is,'' Boeing spokesman Larry McCracken said on Wednesday.

Bloomberg reported Tuesday that, according to people familiar with the matter, an announcement on the sale could come as soon as Wednesday.

GM Chief Executive Officer Jack Smith also declined to comment on the report when asked by reporters at the North American International Auto Show in Detroit.

Hughes shares rose 4-9/16 to 107-1/8 in early trade on the New York Stock Exchange. GM shares rose 1-10/16 to 74-9/16 and Boeing shares fell 6/16 to 42-11/16 on the NYSE.

Hughes technology helped GM in the development of OnStar, which uses Global Positioning System (GPS) satellite technology and wireless communications to link the driver and the vehicle to OnStar call center, where advisors are available 24 hours a day to offer help. It will be standard equipment on 11 model year 2000 vehicles and part of a popular option package on about a dozen more.

GM plans to install XM Satellite Radio Inc. technology in some of its vehicles by 2001, Smith said, offering digital-quality sound coast-to-coast directly from its satellites to listeners in their cars and trucks.

Analysts have speculated for over a year that GM may spin off El Segundo, California-based Hughes as an independent company to boost shareholder value, but an outright sale of Hughes would come as a surprise.

Some analysts have said that GM could spin off one-third of Hughes, worth about $27 billion. GM would hold onto another one-third, and put the remaining one-third into a trust to retire debt and medical benefits obligations.