Orlando Sun Sentinel

Four newspaper companies have filed for Chapter 11 bankruptcy protection since December, though their newspapers continue to operate. Here are some details:

Debt: $13 billion, most from complex buyout in which real estate mogul Sam Zell took the company private in 2007. Had $7.6 billion in assets at time of filing. Generates enough cash that it likely could have made upcoming debt payments, especially with planned sale of the Chicago Cubs, but concluded reorganization necessary for long-term sustainability.

Dailies owned: Los Angeles Times, Chicago Tribune, The Sun of Baltimore, South Florida Sun Sentinel, Orlando (Fla.) Sentinel, The Hartford (Conn.) Courant, The Morning Call of Allentown, Pa., and Daily Press of Newport News, Va., plus Spanish-language Hoy L.A. and Hoy Chicago.

STAR TRIBUNE HOLDINGS CORP., filed Jan. 15:

Newspaper owned: Star Tribune of Minneapolis.

Debt: $661 million, largely from 2007 acquisition from McClatchy Co. by investors led by Avista Capital Partners. Had assets of $493 million as of Dec. 31. Began skipping interest payments in June to conserve cash, and filed for bankruptcy protection after failing to win concessions from unions. Newspaper has asked bankruptcy judge to cancel its contract with printers union; seeking $20 million in annual cost reductions from all unionized employees, $10 million from nonunion employees.

JOURNAL REGISTER CO., filed Saturday:

Dailies owned: New Haven (Conn.) Register, The Middletown (Conn.) Press, The Register Citizen of Torrington, Conn., Daily Local News of West Chester, Pa., Delaware County (Pa.) Daily Times, The Mercury of Pottstown, Pa., The Times Herald of Norristown, Pa., The Trentonian of Trenton, N.J., The Reporter of Lansdale, Pa., The Phoenix of Phoenixville, Pa., The Oakland Press of Pontiac, Mich., The Macomb Daily of Mount Clemens, Mich., The Daily Tribune of Royal Oak, Mich., Morning Sun of Mount Pleasant, Mich., The Record of Troy, N.Y., The Saratogian of Saratoga Springs, N.Y., The Oneida (N.Y.) Daily Dispatch, Daily Freeman of Kingston, N.Y., The News-Herald of Willoughby, Ohio, The Morning Journal of Lorain, Ohio.

Debt: $692 million. Had assets of $596 million as of Nov. 30. Forbearance agreement with lenders letting the company skip interest payments recently expired. Journal Register already has sold two Connecticut dailies and closed several weeklies. Prior to filing, company reached agreement with most of its lenders to cancel its stock and become a private company controlled by its lenders.

PHILADELPHIA NEWSPAPERS LLC, filed Sunday:

Newspapers owned: The Philadelphia Inquirer and Philadelphia Daily News.

Debt: About $390 million, largely from 2006 purchase from McClatchy by investors led by former advertising executive Brian Tierney. Initial loan terms include requirement that newspapers earn higher profit each year, an increasingly difficult feat.