Time Warner Cable has chosen its own poison, accepting a $45 billion acquisition offer from Comcast (News - Alert) after rejecting earlier offers from Charter Communications, and presenting the Federal Communications Commission with another test of U.S. service provider market power.

Ironically, the amount of market share lost by cable operators, collectively, over the last decade to satellite and now telco competitors will make the Comcast deal easier than it would have been in the past. By 2012, the U.S. cable industry market share had dipped below 60 percent.

Without that loss of share, Comcast already would have well exceeded an informal rule that no provider can serve more than about 30 percent of U.S. customers without triggering an antitrust review.

A formal Federal Communications Commission rule to that effect had been in effect until 2001, when the FCC (News - Alert) rule was declared unlawful. The FCC adopted a new version of the rule in 2007, but that version again was struck down by an appeals court in 2009.

The U.S. Court of Appeals for the District of Columbia Circuit said the FCC, “failed to demonstrate that allowing a cable operator to serve more than 30 percent of all cable subscribers would threaten to reduce either competition or diversity.”

Still, most executives voluntarily prefer not to push the informal limit, so Comcast likely will shed enough subscribers to stay at or below the 30 percent limit.

Time Warner (News - Alert) Cable had been the second-largest U.S. cable operator; Comcast clearly the largest. Comcast has about 21.6 million subscribers, while Time Warner Cable has about 11.4 million customers, for a combined total of about 33 million, out of 92.5 million U.S. video subscription customers.

By that reckoning, where the market is defined as all video subscription customers, instead of just “cable customers,” Comcast would have 34 percent market share. That means Comcast will have incentives to divest up to four percent of the newly-acquired customers, to stay at 30 percent share.

Since the beginning of 2010, Time Warner Cable has been losing customers, at least 2.05 million video subscribers, or approximately 16 percent of its subscriber base.

Image via Shutterstock.

That is one good reason for the recent interest in an acquisition by both Comcast and Charter Communications (News - Alert). An acquirer would assume it can do better.

It is possible the deal could falter, especially if Comcast equity price dips significantly. It also is possible there could be adjustments if Time Warner Cable’s equity price were to rise substantially. And Charter could raise its bid, though most seem to think that is unlikely.

Instead, Charter likely would be offered a chance to buy the customers Comcast would shed.