Tribune Co. and MediaNews Group Inc. could each be unable stop advertising losses fast enough, leading them closer to the possibility of defaulting on billions of dollars in debt, Bloomberg News reported Tuesday.

Standard & Poor Analyst Emile Courtney told Bloomberg that Sam Zell's Tribune Co., despite selling assets and debt, could default on debt “as early as December.” William Dean Singleton's MediaNewsGroup Inc. is also in danger, Courtney told Bloomberg.

“In the absence of additional asset sales, we think that it's a possibility (that Tribune would default) as early as December,” Courtney said, Bloomberg reported.

MediaNews could be in violation of its loans on June 30, if its debt-to-cash flow ratio is the 6.53 times it reported Dec. 31, 2007, Standard & Poor stated, according to Bloomberg.

Mark Young, president of Massachusetts investment bank Grist Mill Advisors, and who specialises in media deals, told Bloomberg that if newspaper groups are unable to generate enough money, they could slide into bankruptcy.

“These companies built their portfolios using leverage and executing a strategy with an investment thesis that was clearly flawed,” Young told Bloomberg. “Almost all of these are going to have to go through a restructuring or bankruptcy to come out the other side.”