Mobile phone company Vodafone has approached Germany's biggest cable operator about a possible takeover.

Vodafone said Wednesday It has had preliminary discussions with Kabel Deutschland, which has more than 8 million customers. However, it said there was "no certainty" that an offer will be made.

The move would signal a move into fixed-line TV and telephone services for the UK-based company.

Kabel Deutschland shares were up 9.9 percent at 82.11 euros in afternoon Frankfurt trading. Vodafone shares in London were down 1.6 percent at 182 pence.