FRANKFURT (Reuters) - Germany’s regulator is considering requiring cable TV operators to provide network access to third parties, in a shift that could affect talks on a European merger between Vodafone and Liberty Global.

The proposed deal’s main prize would be to bring together Vodafone’s German cable operation with Unitymedia, Liberty’s local unit, which operate in separate federal states and would, if combined, cover the country.

“The cable operators shouldn’t be too sure of themselves,” Jochen Homann, head of the Federal Network Agency, or BNetzA, told the Frankfurter Allgemeine Zeitung in an interview released ahead of publication on Monday.

In contrast to market leader Deutsche Telekom, the two operators do not have to open their networks for fast broadband internet connections.

“We are now examining whether and which regions cable (operators) have a dominant market position - there are regions where this appears no longer to be out of the question,” Homann told FAZ.

“There, providers may be required to open up their infrastructure to other providers. Price controls would also be thinkable.”

BNetzA has started a market investigation, results of which could be expected next year, the FAZ reported.

Vodafone confirmed in February it was in talks with John Malone’s Liberty Global about buying some of the cable company’s assets in the continental European countries where they both operate.

Deutsche Telekom CEO Tim Hoettges has clashed with Vodafone’s Vittorio Colao, suggesting that the proposed deal would not stand up to anti-trust scrutiny.