MUMBAI: The debate over the proposed takeover of XM Satellite Radio by Sirius Satellite Radio Inc continues, with the latter stating on Wednesday that it still expects to close its deal to merge with XM by the end of this year.

However the combination of the only two US satellite radio companies still faces significant regulatory hurdles, including approval by both the Department of Justice as well as the Federal Communications Commission, says an AP report.

Sirius has also said it complied with a request for additional information from the Department of Justice about the proposed combination.

One of the merger`s chief opponents is the National Association of Broadcasters, which claims the combination of Sirius and XM would create a "monopoly." Other reports suggest however, that satellite radio is not a necessity, and it would continue to compete with terrestrial free radio offerings, Internet radio, MP3 players, and a variety of other mobile entertainment.

The battle for the merger has been going on since February 2007, when Sirius first announced plans to buy out XM in a $13.6-billion deal.