A Countrywide Financial Corp. executive told a U.S. Senate committee on Thursday that 2007 could end up as the company’s worst-ever for subprime mortgage defaults.

In addition, 2006 may become worst single origination year for the nation’s largest lender, said Sandor Samuels, Countrywide’s executive managing director and chief legal officer, during presentation to the Senate Banking Committee.

Samuels urged lawmakers not to “lose sight of the reality that more than 90 percent of Countrywide’s subprime borrowers will not lose their homes to foreclosure,” and warned that lawmakers should not create overly tight restrictions on high-risk mortgages, saying that could lock out many would-be homebuyers.

Previously, 2000 was the Calabasas-based lender’s worst year for defaults, reaching almost 10 percent. Over the past decade, Countrywide’s overall foreclosure rate for adjustable subprime loans has averaged 3.4 percent, Samuels said. The subprime mortgage market represents 7 percent of Countrywide’s home loan volume, compared with 20 percent of the overall U.S. market.

Shares in Countrywide closed down 57 cents Thursday and dropped another 12 cents in aftermarket trading to $36.26.