Beginning last year, Citi Private Bank, which works with clients who have at least $25 million in net worth, held a series of luncheons in cities such as New York and Seattle for existing and potential women customers on topics including finance, entrepreneurship, fashion and health, said Ida Liu, managing director and head of North America Asian clients group. Citigroup is based in New York.

The events, which have been attended by as many as 100 women, have helped contribute to a gain in assets from existing clients, Liu said. The purpose is also to attract new clients who mingle with existing ones and hear about their experiences at the bank, said Liu.

While Citi Private Bank may host events geared to topics of interest to women, it offers all of its clients, regardless of gender, the same investment products and strategies tailored to their individual needs, Liu said.

The tools Wells Fargo uses to meet the financial needs of women clients are "gender neutral," said Jennifer Lee, regional managing director for New York at Wells Fargo Private Bank. Before last month's event, Lee hosted women executives at a June dinner at the Four Seasons Restaurant for another discussion on leadership.

"I have no doubt that we will have new clients as a result," said Lee, whose clients have at least $5 million in investable assets. "No private bank can afford to ignore women clients."

Barclays Wealth, based in London, started holding events across the U.K. this year focused on women, including one in March at the Marylebone Hotel. Last year, the firm also started a magazine called "SmartWoman."

"It's about appealing to the intellect," said Barbara-Ann King, head of the Barclays Wealth female client group in the U.K. Women clients of private banks traditionally came from inheritances or divorces, and now they're seeing more women who have earned their wealth as entrepreneurs or executives, said King. Earlier this year, she started the female client group, which currently focuses on women in the U.K. with generally at least 500,000 British pounds ($773,450) in investable assets.

J.P. Morgan Private Bank, which generally works with people who have at least $25 million in investable assets, usually seeks potential clients by their source of wealth, such as law firm partners or hedge fund managers, said Doug Morris, a spokesman for the New York-based company. Some of the firm's private bankers have reached out to women locally, Morris said.

Banks and advisers trying to add female clients need to tailor their approach without clumping all women together, said Heather Ettinger, managing partner at Fairport Asset Management in Cleveland. Executive women clients are the fastest growing segment of Ettinger's businesss, she said. Ettinger's firm manages about $750 million in assets.

At the annual "Impact" conference for registered investment advisers hosted by Charles Schwab Corp. in November there was a session for the first time on "How to Engage the Female Client." About 240 advisers attended and listened to Anthony DiLeonardi, co-author of "The $14 Trillion Woman."