REUTERS/Philippe Wojazer
The company, founded by French billionaire entrepreneur Patrick Drahi, has been on a dealmaking binge over the last few years, paying out hundreds of millions in fees to investment banks.
In May, it struck a deal to buy US cable group Suddenlink, and acquire assets in Brazil from Portugal Telecom.
It has also bidding for local rival Bouygues, and also sought a deal with Time Warner Cable.
Dexter Goei, CEO of Altice, said in a statement this morning announcing the Cablevision deal: "This acquisition, our second in the cable sector in the US, is the next step in Altice's long-term oriented strategy in the US, one of the largest and fastest growing communications markets in the world."
Goei, like many of the senior leadership team at Altice, is an ex-Morgan Stanley banker.
Scott Matlock, who spent two decades at Morgan Stanley and now works at PJT Partners, sits on the board.
Bernard Mourad, Emmanuel Gueroult and Burkhard Koep, all former senior Morgan Stanley bankers in Europe, all now work for Patrick Drahi.
JP Morgan, BNP Paribas and Barclays acted as financial advisors to Altice.