The number of female students at Harvard Business School (HBS) is expected to drop below 25 percent in January, its lowest level this decade.

No school at Harvard has as low a percentage of women as the Business School and alarmed administrators and students have responded by launching an unprecedented recruiting effort to attract more women.

HBS will begin a new referral program in which students submit names of women they think will make good candidates, and the school plans to purchase the names of women who score well on the GMAT and direct-mail them with information, said Jill H. Fadule, director of MBA admissions.

"In my time here, we've not done something like this before," she said.

The new referral service, headed by Samantha R. Brown, a member of the Women's Students Association (WSA), requests students to submit names of women who are likely candidates for admission but might not apply without proactive contact.

"We're hoping...that we're going to pull in people who might not already be in the system," Brown said.

"We're not looking to recruit women for the sake of recruiting women," she said. "We are only trying to recruit qualified women applicants. ... Even if we move two or three percentage points, I'd be thrilled."

The immediate goal of the referral program is to generate 500 names. Those referred will have their applications judged blindly, but the admissions office will examine the list after decisions are made to see whether the program is effective and to ensure that qualified candidates are not being turned away, said Cynthia L. Rutherford, co-president of WSA.

"Sometimes women, more than men, need more proactive encouragement to say you do fit the bill for this place," Rutherford said. "The career opportunities are much larger than I think a lot of women realize."

While Harvard does have a low number of women, most top business schools are not much better: the leading schools are working to pass the 30 percent mark.

Ultimately, all involved say changes must occur on the undergraduate level in order to achieve a 50/50 gender ratio.

"I think all the stuff that we're doing is more Band-Aid, and ultimately, you need women to start thinking about it earlier," Rutherford said.

Brown said the WSA hopes to attack that part of the problem this year as well. "There are many top undergraduates who don't even contemplate a career in business," she said. "We're...currently designing a program by which HBS women alums will actually go back to their undergraduate institutions and pitch the importance of an MBA."

In addition, WSA members say they will try to improve Harvard's yield--Rutherford said that 3 to 5 women regularly decide "at the very last minute" not to attend.

Brown said this year, WSA members will "open our homes" to prospective students in order to give them a sense of the school.