Dutch operator Ziggo said on Wednesday it had rejected a takeover offer by US Liberty Global media group.

Ziggo said in a short statement it considered the ‘potential offer inadequate and there is no certainty that Ziggo will receive any revised offer’.

The news sent Ziggo shares up 8.4% in Amsterdam.

Liberty Global, which owns Ziggo’s Dutch competitor UPC, took a 12.7% stake in Ziggo in March and has been increasing its interest since then. According to the Financial Times, it now owns about 28.5% of Ziggo, which is the Dutch market leader.