Attracting high-net-worth investors is a high priority at any firm, and Merrill is no exception. Ethical investing resonates with many members of this sought-after group. "Our mission at the private banking and investment group is to help people like you, at the top tier of wealth, maximize and manage your wealth and legacy," says chief investment officer Christopher Wolf in a video appeal. "For many people, that means incorporating individual goals, objectives and values into the wealth management process."

But it's the legwork of individual advisors walking the SRI walk that has helped the firm ramp up its presence in the values space. One of those advisors, Mary King, became interested in socially responsible investing in the mid-1990s when she was a junior at Harvard Divinity School majoring in economics and religion. "It was exciting to me that my faith and spirituality could be applied to the financial markets," she says.

During her junior year in college, she became an intern at KLD Research & Analytics, a leading socially responsible investment firm in Boston. The firm needed someone to research issues of concerns to Catholics, and King's background fit the bill perfectly. Her thesis, titled "Catholic Investing-The Effect of Screens on Portfolio Returns," was published in the Journal of Investing in 2001. She concluded that a portfolio screening for religious values performed almost the same as one that didn't.

After graduation, she worked for a few years as a writer and researcher for a religious Web site. "When I gave speeches, people would tell me they had trouble finding financial advisors who could integrate their principles into the investment process," she recalls. "I realized there was a niche that needed filling."

She joined Merrill in 2002, and began the slow process of building a client base by "putting a lot of miles on my car, going out to lunch a lot, gaining a few pounds and getting rejected." Her initial clients came from conferences and Christian singles groups.

Today, she uses third-party money managers and separately managed accounts for her clients, who have a minimum of $1 million to invest and come mainly through referrals. She maintains her own list of screens and approved stocks, and checks to make sure outside managers are abiding by her guidelines.

Although most of her clients follow faith-based directives, she says religion and social concerns share a lot of common ground. Religious screens for tobacco, alcohol, weapons, nuclear power and gambling, for example, are present in many SRI mutual funds. To those, she adds additional screens for companies involved in abortion or pornography.

Many forbidden firms might seem relatively harmless at first glance. Comcast, for example, gets the boot from King's portfolios because it derives revenues from adult films. She says many faith-based investors, particularly women and those under 50, want the environmental screens as well as the faith-based ones.

When Hilary Giles started at Merrill seven years ago she didn't intend to specialize in environmental investing, although her husband's job at a solar energy company certainly sparked her interest in the field. Her clients nudged her in that direction when they began asking how they could invest in ways to improve the environment.

Today, she and her partner manage some $500 million for clients of the firm's private banking and investment group, which requires a $10 million investment minimum. They typically range from ages 30 to 50 and "tend to be progressive both in their portfolio construction and philosophies." About one-third request green screens or preferences for clean energy companies, either as one-off investments or as part of a more encompassing green portfolio.