RealNetworks and Viacom's MTV Networks are talking about restructuring their Rhapsody joint venture -- aiming to possibly reduce the Seattle company's ownership stake and end its majority control of the music service, according to a regulatory filing.

"These negotiations are focused on a potential restructuring of RealNetworks' and MTVN's relative economic rights in the joint venture and on their relative abilities to exercise control over decision-making to enable Rhapsody to operate more independently of either party," says the filing, made public last night. "If these discussions result in a definitive agreement, RealNetworks may agree, among other things, to adjust the corporate governance and/or management structure of Rhapsody and to reallocate the ownership of Rhapsody between RealNetworks and MTVN such that RealNetworks' percentage ownership of Rhapsody could be reduced from 51% resulting in both parties owning 50% or slightly less."

The filing notes that the talks are in preliminary stages, and nothing may come of them. But the negotiations suggest that at least one of the companies isn't content with the status quo at Rhapsody. Subscribers to the music service have been declining steadily, from 800,000 to 700,000 over the past three quarters.

Who might be brought in as an additional owner? PaidContent.org, which first reported on the filing last night, speculates that MySpace would make sense. Rafat Ali quotes a RealNetworks spokesman saying that the company was required to disclose the MTV talks due to the strict requirements of a tender offer that would let employees exchange underwater stock options for less of them at a new strike price.

BusinessWeek in September made the case for the potential benefits of RealNetworks selling Rhapsody entirely. On stage at the FiRe Global West Coast 2009 conference in September, RealNetworks CEO Rob Glaser downplayed the possibility when asked about it on stage by John Cook of TechFlash.

"I would say, in the current economic environment, it's much more appealing, generally speaking, to be buyers of assets than sellers of assets," Glaser said at the time. "In this particular business, the challenge is, we've tried a number of different ways to be partners with music companies. We are constantly looking out for ways to have more flexible relationships with them, and if there's a way to have a more flexible relationship with them ... we'd be open to doing that. But that would be the kind of thing I'd be thinking about, mostly."