Fox Sports is looking to take over the world — or at least the regional sports networks in the U.S. They recently purchased 49 percent of the YES Network for $1.5 billion and secured the rights to the Los Angeles Dodgers television broadcasts for the next 25 years with their $6 billion offer.

John Ourand of Sports Business Daily reports that Fox is working with Orioles owner Peter Angelos to buy out the Mid-Atlantic Sports Network. According to the story, Fox’s efforts “are not moving smoothly.”

Sources say Fox has spent the past several months in on-again, off-again talks to acquire all or part of MASN, which holds the rights to the Orioles and Nationals. Fox currently is not in that market and this would fit with its strategy to build on its RSN business.

Comcast, which operates Comcast SportsNet Mid-Atlantic, also had preliminary talks, which sources say did not progress far.

Several sources described those negotiations as currently off, saying that Angelos opted not to sell the RSN.

Fox’s involvement in talks with MASN came at MLB’s urging, sources said. MASN still is involved in a rights fee dispute with the Nationals. That dispute hasn’t been resolved, though both parties met at MLB’s New York offices last week. MLB hoped that a deal with Fox would solve the dispute. MASN and Fox have not met for several weeks, and no further talks are scheduled.

I certainly don’t know much about the inner-working of television deals — although I don’t believe Angelos is secretly pocketing $500 million like some do — but according to Wendy Thurm’s research at FanGraphs, the regional networks that are not operated by team ownership seem to generate more revenue than those that are.

MASN generated $29 million for the Orioles last year.