Journal Register Co., the company that publishes newspapers in New Haven, Middletown and Torrington, Wednesday filed for bankruptcy protection and its parent company is seeking a “prompt sale.”

John Paton, CEO of Digital First Media, which operates Journal Register and MediaNews Group, wrote on his blog Wednesday that he expects an auction and sale to take about 90 days “and I am pleased to tell you the company has signed a stalking horse bid for Journal Register Company for 21st CMH Acquisition Co., an affiliate of funds managed by Alden Global Capital LLC.”

A stalking horse bid is an initial bid on the assets of a company that has filed for bankruptcy from an interested buyer chosen by the company. The practice allows the company to avoid low bids on its assets.

The Journal Register has local news operations in 10 states, according to its web site. In Connecticut, the company publishes the New Haven Register, the Middletown Press and the Register Citizen.

This the second time Journal Register has filed for bankruptcy, and it is another sign that newspapers continue to struggle with declining print advertising revenues.

Paton wrote that Journal Register emerged from a 2009 bankruptcy restructuring with approximately $225 million in debt and costs for leases, pensions and other liabilities “that are now unsustainable and threaten the company’s efforts for a successful digital transformation.”