A woman walks past the Merrill Lynch logo outside their offices in the City of London March 6, 2009. REUTERS/Andrew Winning

NEW YORK (Reuters) - Female chief executives earned just 58 percent of what their male counterparts did in 2008, and their compensation packages were slashed three times as much as their male peers, according to a survey released on Monday.

Corporate governance research firm the Corporate Library said total realized compensation -- which includes base salary, bonuses, perquisites, benefits, and the value realized on the exercise of options and vesting of other equity -- fell by a median of 18.5 percent in 2008 for female CEOs.

In the same period, the compensation of male CEOs fell 6.1 percent, the survey revealed.

Top female chief executives’ median base salary was $40,000 higher than that for male CEOs, but men’s’ discretionary bonuses were more than 3.5 times larger than those given to females, and men’s perquisite payments were nearly twice the amount received by women, the survey said.

Female CEOs earned on average 58 percent of what males earned in realized compensation, the Corporate Library said.

United Therapeutics Corp’s Martine Rothblatt was the only female CEO among the top 150 earners of 2008, with total compensation worth $21.8 million.

Among female CEOs, Rothblatt was followed by Avon Products Inc’s Andrea Jung, with $13.9 million in total realized compensation, and TJX Companies Inc’s Carol Meyrowitz, with $12.8 million.

The survey was based on compensation data of 2,703 U.S. listed companies. Women CEOs accounted for only 3 percent of the total, the Corporate Library wrote in the report.

The survey also found that women are more likely to serve as CEOs at smaller companies.