WASHINGTON —  Federal regulators formally approved the merger of the nation's only two satellite radio operators Friday, ending a 16-month-long drama closely watched by Washington and Wall Street.

Sirius Satellite Radio Inc.'s $3.3 billion buyout of rival XM Satellite Radio Holdings Inc. will mean 18 million-plus subscribers will be able to receive programming from both services. Executives say it will mean huge cost savings that will lead to a first-ever profit for the relatively nascent industry.

The Federal Communications Commission voted 3-2 to approve the buyout, with the tie-breaking vote coming Friday night from Republican commissioner Deborah Taylor Tate.

Tate had insisted that the companies settle charges that they violated FCC rules before she would approve the deal. The companies agreed this week to pay $19.7 million to the U.S. Treasury for violations related to radio receivers and ground-based signal repeaters.

FCC Chairman Kevin Martin confirmed the final 3-2 vote Friday night.

"I think it's going to be, in the end, a good thing for consumers and be in the public interest," he told The Associated Press.

The approval appeared to hit a glitch on Friday when a dispute surfaced between the chairman and Tate over the enforcement issue, but differences between the two were quickly resolved, and the approval went forward.