The Securities and Exchange Commission has opened an informal probe into stock sales by Countrywide Financial Corp Chief Executive Angelo Mozilo, the Wall Street Journal said on Wednesday.

Countrywide, the largest U.S. mortgage lender, is one of a dozen companies the SEC is looking into in connection with the subprime mess, the newspaper said citing people familiar with the matter.

A spokesperson for Countrywide said it does not comment on communications with regulators.

An SEC spokesman had no comment. But the agency has previously said it is looking hard at the general issue of whether executives are illegally trading on insider information and using a preset trading plan to avoid suspicion.

North Carolina Treasurer Richard Moore has raised questions about the timing of Mozilo's stock sales as problems in the subprime mortgage crisis surfaced.

Last week, Moore said he sent a letter to the SEC asking the agency to investigate Mozilo's use of stock options and the timing of changes made to his trading plans.

Countrywide plans to cut 10,000 to 12,000 jobs, or up to 20 percent of its work force and said earlier this month it expected a $125 million to $150 million pretax restructuring charge from the move.

Shares of Countrywide closed down 4 percent at $17.35 on the New York Stock Exchange.

(Reporting by Dan Wilchins and Rachelle Younglai)