Connecticut-based People’s United Bank and M&T Bank face 12 lawsuits challenging their proposed merger and have disclosed additional information about the deal in response to the legal actions.

M&T and People’s United said an SEC filing that the banks do not believe that the claims have merit and denied that additional disclosures were required or necessary. The banks said they decided to release additional information in part to avoid delaying the merger.

Among the allegations in the lawsuits are claims that the registration statement relating to the proposed merger was incomplete and misleading. People’s United also said in the SEC filing that it has received written demands from purported stockholders about the merger.

“M&T, People’s United and the other named defendants deny that they have violated any laws or breached any duties to M&T’s shareholders or People’s United’s stockholders, as applicable,” the banks said in the SEC filing. “… To the contrary, M&T and People’s United specifically deny all allegations in these Merger Actions that any additional disclosure was or is required.”

In addition to avoiding delays in the merger or other adverse effects, the banks also said they released the additional information to minimize the costs, risks and uncertainties involved with defending the legal actions challenging the merger.

The new disclosures include additional information about the background of the merger, what was discussed with People’s United’s board of directors, the pricing of the deal and financial information used in the deal.

Lawsuits against mergers are common, and a couple of the plaintiffs involved in the lawsuits also challenged Boston Private’s merger with Silicon Valley Bank, including Shiva Stein, known as a serial litigant.

The all-stock transaction valued at $7.6 billion between People’s United and M&T would create a combined company with approximately $200 billion in total assets and around 1,100 branches from Maine to Virginia. People’s United has branches throughout Massachusetts.