Washington, D.C. ? 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 tiebreaker coming Friday night from Republican commissioner Deborah Taylor Tate.