Ford Motor Co. (F) will begin offering Sirius Satellite Radio (SIRI) as a factory-installed option in up to 1 million vehicles over two years beginning this summer, the companies said on Tuesday.

Ford in October said it would put Sirius in about 20 vehicle lines but did not set a subscriber target.

Janco Partners analyst April Horace said Ford's 1 million target for its 2006 and 2007 models was a positive sign for Sirius, which ended 2004 with about 1.1 million customers.

"By stating they're going to go into 1 million vehicles and identifying the vehicles, Ford is giving more color and clarity about its satellite radio plans," Horace said.

The auto market is seen as a key growth area for both Sirius and its bigger rival XM Satellite Radio (XMSR), which both provide nationwide radio services for a monthly fee.

But Horace noted that Ford, an important partner for Sirius, has been slower to install satellite radios than rivals such as General Motors (GM), a major XM partner.

GM had 1 million customers using XM's service by December. Another automaker Toyota Motor Corp. (search) has said it would offer an option to put XM radios starting in 2006.

Sirius shares were up 6 cents at $7.54 in morning trade on Nasdaq where XM stock was up 7 cents at $36.29.

Starting with the 2006 model year, Ford said it was planning to offer factory-installed Sirius on its popular F-150 pickup trucks, as well as on the Ford Explorer, the Lincoln Mark LT and Mercury Mountaineer.

About 80 percent of all Ford and Lincoln Mercury vehicles will eventually have Sirius as a factory-installed option, Sirius and Ford said.

Pricing will be announced at a later date, the companies said. Sirius has attracted much attention since it signed a deal with controversial radio host Howard Stern (search) in October.