Big-3 credit ratings plummet again

General Motors Corp., Ford Motor Co. and Chrysler LLC had their credit ratings lowered one step further into junk status by Standard & Poor's over concern that shrinking U.S. auto sales will reduce cash flow.

The three U.S. automakers are each rated B-, six levels below investment grade, S&P said today. GM's partly owned finance unit, GMAC LLC, was also lowered to the same rating.

“Liquidity for all three automakers is adequate for now, but will be significantly reduced in the second half of this year and during 2009 by continued heavy losses and cash outflows,'' wrote S&P analyst Robert Schulz in a statement.