The Dolans’ Cablevision Systems — in a move guaranteed to upset some shareholders — agreed over the weekend to pay $1.36 billion for cable provider Bresnan Communications.

The Dolans sealed the deal despite the shares taking a 5.6 percent hit last Wednesday when takeover talks were first reported.

Some shareholders want extra cash from the profitable but slow-growing Cablevision used for dividends — and not risky deals. Cablevision in 2008 bought Newsday in what turned out to be a poor investment.

There also may be limited synergies in running Cablevision and Bresnan, according to one source.

Cablevision is looking to help Bresnan add more phone and data services in its region, replicating its success in the New York area selling its “triple-play.”

The company serves five million New York area customers. Bresnan, whose headquarters is in Purchase, NY, has 320,000 Montana, Wyoming, Colorado and Utah customers.

“The Dolans are the best at running cable systems on the planet,” a source said, explaining why he thought it was a smart acquisition.

Cablevision also might find Bresnan particularly attractive because its main competitor is the relatively weak Qwest Communications.

In addition, the Long Island-based company is expected to announce a share buyback today, according to a report on WSJ.com, citing sources.

The Dolans, in a surprise, turned to Citigroup for advice, according to a source, on buying Bresnan after using JPMorgan Chase to spin off Madison Square Garden in February.

A Cablevision spokeswoman did not return calls for comment.