UPDATE 1-Dolans say will not raise Cablevision offer

(rewrites throughout)

By Yinka Adegoke

NEW YORK, Oct 16 (Reuters) - The Dolan Family said on Tuesday they will not raise their $10.6 billion bid to buy out New York-based cable operator Cablevision Systems Corp (CVC.N: Quote, Profile, Research, Stock Buzz) in the face of mounting opposition from shareholders.

Two shareholder advisory firms, Proxy Governance and RiskMetrics Group, joined a small but influential number of shareholders who have expressed doubts on whether the Dolans are offering fair value for the company ahead of vote on the bid on Oct.24.

The increasingly negative sentiment towards the Dolans' bid prompted Citigroup analyst Jason Bazinet to cut Cablevision's stock to a sell from a hold, saying it looked less likely the bid would go through at the Dolans' $36.26 per share offer price.

But in a statement late on Tuesday, Cablevision Chief Executive James Dolan rebuffed any suggestion that his family might consider raising its bid to satisfy such shareholders.

"I want to state emphatically that there will be no modification of the family's accepted offer."

As the shareholder vote approaches, the Dolan offer to privatize the company is being challenged by key shareholders who believe Cablevision is worth as much as $50 a share.

As well as cable systems serving 3 million subscribers in the valuable New York area, Cablevision owns cable networks, sports franchises like the New York Knicks basketball team and venues like Madison Square Garden and Radio City Hall.