HOLLYWOOD — Nascent radio satcaster XM Satellite Radio has received a $250 million vote of confidence from a new group of investors that includes such strategic allies as General Motors, radio giant Clear Channel Communications and TV satcaster DirecTV.

As part of General Motors’ $50 million investment, the automaker has agreed to incorporate XM’s satcasting technology into its new cars and trucks under a long-term distribution deal.

Analysts said recognition from a corporate titan like GM eventually should boost demand for national radio satcasting services in the eyes of investors and consumers. XM is one of two U.S. satcasters set to launch satellite-delivered subscription programming services by the end of next year.

DirecTV, whose parent company is owned by GM, also sunk $50 million into XM, while radio and TV operator Clear Channel ponied up $75 million. A private group of venture capital firms, comprising Columbia Capital, Telecom Ventures and Madison Dearborn Partners, forked over another $75 million.

WorldSpace bought out

In connection with the new coin flowing into XM, the satcaster’s parent company, American Mobile Satellite Corp., has bought out its former partner in XM, WorldSpace Inc.

XM Satellite prexy Hugh Panero described the satcaster’s new partners as a “dream-team alliance.”

Separately, XM competitor CD Radio announced Tuesday a programming pact with pubcaster National Public Radio. NPR will provide news, talk and en-tertainment programming for two channels on CD’s planned 100-channel service.

Both XM and Gotham-based CD Radio’s services will deliver to subscribers audio programming via a palm-sized satellite dish and a “smart card” receiver device inserted into a regular cassette or compact disc player. CD Radio has a patent-infringement suit pending against XM Satellite, and it’s unclear how that legal dispute might impact XM’s distribution deal with General Motors.