Updated: The final legal hurdle to the merger of the two satellite radio giants XM and Sirius has finally been cleared - unofficially. FCC approval of the deal was secured after the two companies agreed to pay fees in relation to prior violations of FCC regulations.

"I think it's fair to say an agreement in principle has been reached," said FCC Chairman Kevin Martin in an interview with the Wall Street Journal.

The violations the companies agreed to pay fines for related to in-car and in-home devices using unregulated FM transmitters and some of the terrestrial repeater network for the signals, used to enhance reception in cities and other areas where geographical constraints limit satellite signal. XM is expected to pay $17 million while Sirius will cut a check for $2 million to the U.S. Treasury. The fines, though large, are small in comparison to the value of the merger.

Original: After gaining approval from the U.S. Department of Justice's antitrust division in March, the only remaining hurdle in the way of the deal's completion was FCC approval. That hurdle will soon be cleared, according to the FCC's Chairman Kevin Martin, who has confirmed that he will support the transaction.

The deal has several proposed commitments by both Sirius and XM that are designed to improve the fairness of the merger and ensure the public benefits from it.

The three key elements of the deal include a cap on prices, provision of equipment that works with either service and the availability of 'a la carte' programming, meaning individual channels and programming packages can be chosen by the consumer.

Together Sirius and XM have over 17 million customers in the U.S., reports Automotive News and as the only two satellite radio providers, the companies are merging to unify their resources in the face of tough competition driven by the next generation in mobile music and programming, including iPod-integrated MP3-capable car stereos, HD radio and music phones.

Final details of the deal must still be approved by the FCC as a whole, but with the backing of the chairman, it's likely the current proposal will find a positive result.

For more details on the previous steps of the deal, read our earlier coverage.