Cablevision ( CVC) rejected a sweetened takeover bid by the company's controlling Dolan family, calling the offer inadequate.

The company announced late Tuesday that the $30-a-share offer, which valued the cable television giant at $8.9 billion, "does not represent fair value for the Company's public shareholders nor does it contemplate a transaction that is in their best interest."

The Dolan family had declared its most recent offer on Friday , which raised the bid from $27 a share, its "best and final" and said the uncertainty hanging over the negotiations were possibly harming the company.

The family also said its offer would expire by the close of business on Wednesday.

But whether the negotiating is over remains to be seen. A large number of shareholders, who have seen the stock trade around the $28 level for about three months, continue to believe the stock is worth more.

Earlier Tuesday, Bank of America analyst Douglas Shapiro downgraded the stock, largely on the premise that the $30-a-share bid would succeed.

Shapiro wrote that he inferred that Cablevision's special committee had received a fairness opinion that is "close enough to $30 that the two sides may be able to agree to a price relatively close to that level." He also wrote that the financing provided by the Dolan family's advisers "does not leave a lot of room to raise the bid substantially."

Shares of Cablevision closed Tuesday up 10 cents to $28.46.