Acquisitive Netherlands-based telecoms company Altice has entered into a deal to buy U..S. cable television provider Cablevision at $34.90 a share, both companies announced Thursday morning.

The boards of both companies have approved the deal, has been valued at $17.7 billion.

Altice said in a statement issued Thursday morning that the deal is expected to close in the first half of 2016 and will be financed by a combination of a $14.5 billion share issue, $3.3 billion in cash and cash on hand in Cablevision.

Altice, which sought and failed earlier this year to buy time Warner Cable, will pay $34.90 per share for Cablevision. Altice was beaten to TWC by Charter Communications, whose $55 billion purchase of the business is still being closed.

Read More Bouygues shuns Altice's bid for telecom arm

In June Altice, which sells cable-based services including pay TV, broadband and fixed lines in several European countries as well as the French West Indies and Dominican Republic, reportedly tried to buy the telecoms unit of France conglomerate Bouygues.

Reuters reported that the offer as worth 10 billion euros ($11.2 billion) but was snubbed by Bouygues.

Altice entered the U.S. cable market in May, when it bought Suddenlink Communications in a deal valuing the company at $9.1 billion.

Read More Altice enters US cable market with Suddenlink buy

In a recent interview with the Wall Street Journal, Altice Chief Executive Patrick Drahi said that his vision was to take bundled cable services - so-called quadruple play offers because the bundles include TV, mobile, fixed telephone lines and high-speed broadband - to the U.S., where such deals don't exist on a large scale.

The WSJ noted that New York-based Cablevision, which is the fifth largest U.S. cable company and eighth-biggest pay-TV provider, was an obvious acquisition target in an industry where size matters and consolidation is happening quickly.

Media analyst Rich Greenfield told CNBC's "Squawk Box" Thursday that he's surprised Altice is paying so much for Cablevision, controlled by the Dolan family.

But BTIG's Greenfield said Altice is known as an "incredible cost cutter" and there's probably some "fat" in the Cablevision organization.

- Andrew Ross Sorkin and Matt Belvedere contributed to this report.

CORRECTION: An earlier version of this story transposed the per-share price offered by Altice for Cablevision as $39.40.