U.S. broadcaster E.W. Scripps' board unanimously rejected Sinclair's $622 million acquisition proposal, saying it was not in the best interests of the company and its shareholders.

Sinclair, which already owns 8.2% of Scripps, made the unsolicited bid last month to buy all remaining shares for $7 apiece, including $4.28 in stock. The deal would have given Scripps investors about 12.7% of the combined company.

While rejecting the larger rival's bid on Tuesday, Scripps added it remained open to evaluating opportunities to enhance shareholder value, including any future proposals.

Sinclair, in a statement on Wednesday, said it was "disappointed that despite Scripps encouraging Sinclair to make a proposal, Scripps' board rejected (it) without engaging."

Sinclair said its offer addresses concerns for Scripps' stakeholders with strategic and financial benefits. The company urged Scripps to engage, saying the shareholders deserve a full and fair evaluation.

Scripps' rejection follows a defensive step taken by the company in late November, when it adopted a limited-duration shareholder rights plan, commonly known as a poison pill, days after Sinclair went public with its approach.

Sinclair framed the bid as a way to expand its broadcast television footprint at a time when station owners are seeking greater scale to offset cord-cutting and softer advertising markets.

Scripps, which owns a portfolio of local TV stations as well as national networks including Court TV and Ion, has been working to manage debt and invest in its news and sports programming as audiences fragment across streaming platforms.