European telecoms group Altice will become a major force in the lucrative US cable market after it agreed to buy fourth-largest operator Cablevision for a mix of cash and shares in a deal worth $17.7 billion including debt.

The move is the latest foray by French-Israeli billionaire and Altice founder Patrick Drahi, who built a telecoms and cable empire in recent years via debt-fuelled acquisitions in France, Portugal and Israel.

Drahi entered the US in May by buying small regional cable group Suddenlink for $9.1 billion and had declared he would do more acquisitions so as eventually to earn half of Altice's revenue there.

In talks that began in June, Drahi managed to convince Charles Dolan, the patriarch of the Irish-American family that owns Cablevision, to part with the asset they had long said they would not sell.

Altice will pay $34.90 in cash per share, a 22 per cent premium on Wednesday's closing price of $28.54, and a person close to the company said it will finance the deal with $3 billion from a share sale and $7 billion in debt.

Cablevision has 3.1 million customers in the New York, Connecticut and New Jersey area.

Drahi is expected to apply his cost-cutting zeal to generate $900 million in synergies a year at Cablevision, but will have to contend with fast-changing competition as consolidation picks up among US cable groups seeking to cope with changing customer viewing habits.-Reuters