In a compensation program that has drawn angry protests from lawmakers, Fannie Mae and Freddie Mac expect to pay about $210 million in retention bonuses to 7,600 employees over 18 months, according to a letter from the mortgage companies' regulator.

The maximum retention bonus for any individual executive under the plan will total $1.5 million during the 18 months ending in early 2010, according to the letter to Iowa Republican Sen. Charles Grassley, which provides previously undisclosed details about the bonuses.

The regulator, James Lockhart, director of the Federal Housing Finance Agency, said in the letter that about $51 million of the payouts were made in late 2008 and the rest are to be made this year and early in 2010.

In the letter, a copy of which was reviewed by The Wall Street Journal, Mr. Lockhart defends the bonuses as vital to retaining talent at the two companies, the main providers of funding for U.S. home mortgages. Fannie and Freddie, which reported combined losses of about $108 billion for 2008, are being propped up by capital infusions from the U.S. Treasury.

The retention-bonus plan has stirred controversy in Washington since it was highlighted in a March 18 Wall Street Journal article.