BERLIN — Shares in Germany's biggest cable operator are up after Kabel Deutschland received a preliminary takeover proposal from U.S. firm Liberty Global.

Kabel Deutschland confirmed Liberty Global PLC's approach Tuesday, only days after British rival Vodafone PLC said it was also in early takeover talks with the company.

London-listed Liberty Global — a cable TV and Internet provider controlled by media mogul John Malone — is already Germany's second biggest cable operator through local subsidiary Unitymedia Kabel BW.

Kabel Deutschland Holding AG has over 8 million customers compared with Unitymedia Kabel's 7.1 million.

Kabel Deutschland shares rose by 3.6 percent to 85.64 euros early afternoon Tuesday.