NEW YORK (Reuters) - Banking and mutual fund company Mellon Financial said it took a 15 percent equity stake in hedge fund group Optima Fund Management for an undisclosed amount of money.

The move follows on the heels of last year's alliance between the two firms aimed at giving Mellon's high net worth clients access to hedge funds, the year's hottest investments. As demand for these loosely regulated funds rises, many of the nation's leading money management firms are scrambling to offer hedge funds, both to satisfy customer demand and to keep fund managers who had been leaving to set up their own funds. Mellon will now be the only US-based financial services company to offer Optima hedge fund investments. New York-based Optima manages $1.7 billion in assets and offers more than 22 multi- or single-adviser hedge funds, both on-shore and off-shore, through its Bermuda-based office.