Over the past few years, one of Wall Street's favorite parlor games has been betting on who will buy Merrill Lynch ( MER). At various times, speculation has centered on HSBC ( HBC), Bank of America ( BAC), Bank One ( ONE) and even Wells Fargo ( WFC). Even though the bear market has taken a big bite out of Merrill's hide, it remains an attractive catch because of its huge retail brokerage operation, wealthy asset-management clientele and investment bank. At the same time, it's seen as needing a mate, because it remains a laggard in fixed-income trading and corporate lending. But to date, while there's been flirting, there's been nothing close to a full-blown courtship. Merrill, for now, appears dead-set against a merger, for a variety of reasons. Earlier this year, sources say, the nation's biggest brokerage rebuffed an overture from ING Group ( ING), the Dutch-based banking and insurance conglomerate, which is looking to build on the success of its ING Direct online bank. Neither ING nor Merrill would comment. But an investment-banking source said ING approached Merrill about a possible deal sometime this year, and was rebuffed. Lawyers familiar with the talks said it was ING that broke off the negotiations.