Cracks are emerging in private equity’s glass ceiling, with a handful of buyout firms looking to recruit more women. The Carlyle Group, Bain Capital, Riverside Co., and Solera Capital are among those that say they are working to bring females into the fold. Still, the firms are grappling with the legacy of a male-dominated industry, and are having a tough time finding enough women to fill senior positions that require years of intense deal-making experience. Many are settling for staffing their junior ranks with more women.

“There are not oceans of fully formed, partner-level private equity professionals” who are women, the chief executive officer of Solera Capital, Molly Ashby, said. A New York City-based firm, Solera Capital has seven women on its nine-person deal team. “If you went and said, ‘Gee I’d like to start a firm today and bring a bunch of diverse and female partners in,’ unless you did a giant snatch on Solera, it’s going to be quite difficult.”

Hard data on the number of women in private equity is difficult to come by, given the secretive and fragmented nature of the industry. But a look at the senior ranks of a handful of large private equity firms makes it clear that women are scarce in the upper echelons. For example, the Blackstone Group has just five women out of 58 senior managing directors, while the Carlyle Group has only nine women out of 128 managing directors.

The Carlyle Group has created a mandate to hire more females. The Washington, D.C.-based firm hires 15 new associates yearly, and since 2004 roughly half of them have been women, according to a manager in Carlyle Group’s human resources department, Annie Paydar.

Bain Capital is also trying to diversify its two-year associates program, with women accounting for 40% of its new hires in the last several years.

Competition to hire talented people is always fierce, regardless of gender, the director of human resources for Riverside, Peggy Roberts, said. Since 2006, 20% of the New York- and Cleveland-based firm’s non-administrative hires have been women. The firm has also staffed its new nine-person deal sourcing division with five women.

“We’re trying to mirror the companies that we buy,” Ms. Roberts said. “It’s such a competitive hiring market. I think our diversity gives us an interesting leg up. It is a huge attraction and retention tool.”

It is easier to bring women in the door when a firm already has a number of them in senior roles, she added. For this reason, Riverside makes a point of having female job candidates sit in on deal meetings run by the managing partner who co-manages the firm’s $750 million buyout fund, Suzanne Kriscunas.

Ms. Ashby of Solera Capital said her firm has found it “fairly easy” to recruit new women, as “they believe that they’ll be welcome here.” Solera Capital, which buys retailers and consumer goods businesses, may be the only private equity firm in the country in which men are the minority. Fourteen of its 17 investment professionals are women.

Ms. Ashby predicted that the gender gap in private equity would narrow in the next decade as big firms modernize and more operations that place a premium on fostering diverse talent are created. Credit Suisse’s private equity group began hosting a conference for women in private equity in 2000, when there were just 35 attendees. “This year we had close to 150 women,” a managing director and vice chairman of the private equity arm of the investment bank, Nicole Arnaboldi, said. “If that’s any barometer, clearly there are a lot more women in private equity in a seven-year period.”