BRUSSELS (Reuters) - EU antitrust regulators handed a 125-million-euro (109.37 million pounds) fine to French telecoms and cable group Altice on Tuesday for finalising its 2015 takeover of PT Portugal without first waiting for the official go-ahead.

The European Commission said certain provisions in the purchase agreement showed that Altice exercised decisive influence and veto rights over the Portuguese company even before the deal was cleared.

"Altice breached both the notification and the standstill obligations. The Commission considers that these infringements are serious because they undermine the effective functioning of the EU merger control system," the EU competition enforcer said.

Reuters reported on April 18 that the company would be hit with a hefty fine for breaching EU merger rules.

(Reporting by Foo Yun Chee and Robert-Jan Bartunek)