Countrywide Financial Corp., America’s largest mortgage lender, announced that more borrowers with good credit were falling behind on their loans and that the housing market might not begin recovering until 2009 because of a decline in house prices that goes beyond anything experienced in decades, Reuters reported.

The news from Countrywide initiated a sell-off Tuesday in the stock market, which is at its most volatile in more than a year.

Countrywide’s assessment signaled a change in the substance and tenor of how housing executives are publicly describing the market. A couple of months ago, some executives were predicting a relatively quick recovery and saying that most home loans would be fine, with the exception of those made to borrowers with weak credit who were stretched too far financially.

In a conference call with analysts that lasted three hours, Countrywide’s chairman and chief executive, Angelo Mozilo, said home prices were falling “almost like never before, with the exception of the Great Depression.”

Mozilo said that because of a large number of homes on the market, the housing sector would continue to suffer until sometime in 2008 and not begin recovering until 2009.