Sirius Satellite Radio Inc.’s proposed $4.59 billion acquisition of XM Satellite Radio Holdings Inc. won American antitrust clearance to create a single American satellite-radio provider. Shares of both companies surged.

The Justice Department, in approving the deal, said the combined company won’t be able to raise prices profitably because of competition from such forms of audio entertainment as broadcast radio and MP3 players.

“We just simply found the evidence did not support a challenge to the transaction under the antitrust laws,” the Justice Department’s antitrust chief, Thomas Barnett, told reporters. There wasn’t enough evidence the merger “would substantially lessen competition or harm consumers,” he said. The companies are still awaiting approval by the Federal Communications Commission. The chairman of the FCC, Kevin Martin, signaled March 20 that the agency is close to a decision, telling reporters he had asked its staff to draft “various options.” The commission “is looking at it,” a spokeswoman from the FCC, Mary Diamond, said yesterday. XM Satellite Radio rose 16%, or $1.85, to $13.79 as of 4 p.m. in composite Nasdaq Stock Market trading. Sirius rose 9%, or 25 cents, to $3.15.

The companies proposed the combination to stem billions of dollars in losses incurred in attracting talent, sports deals, and subscribers and to reach profitability sooner than they could on their own. Sirius, based in New York, features Howard Stern and Nascar and has 7.67 million subscribers. Washington-based XM, with Oprah Winfrey and Major League Baseball, has 8.57 million. “They still have only a fraction of the broadcast audience,” an analyst with Barrington Research in Chicago, James Goss, said in an interview before the decision. “On a combined basis their strength is in creating a more efficient business model by not having duplicate costs and not having consumers being forced to choose one or the other.”