(Adds comment by Treasury official) WASHINGTON, July 1 (Reuters) - U.S. government-controlled mortgage finance companies Fannie Mae and Freddie Mac on Wednesday disclosed huge pay raises for their chief executive officers, part of a plan sanctioned by their regulator to attract and retain talent. Fannie Mae CEO Timothy Mayopoulos and his counterpart at Freddie Mac, Donald Layton, will each now earn $4 million a year, up from previous annual salaries of $600,000. The Federal Housing Finance Agency, an independent regulator, slashed executive pay at the two companies in 2012. Before then, executives could earn as much as $6 million a year. Freddie Mac and Fannie Mae disclosed the pay raises in filings to the Securities and Exchange Commission. The increases came despite opposition from the Obama administration.