Wallace has a strong buy on AOL, for which his firm hasn't done underwriting. Other concessions that regulators might be more likely to impose wouldn't have such a negative effect on AOL Time Warner, Wallace says. Those could be that AOL would have to sell its stake in Hughes Electronics, that Time Warner would have to back off its proposed joint venture with EMI Group ( EMI ), or that AOL would have to make its instant messaging system compatible with those of its rivals. Instant messaging "on its own is not a huge revenue driver for the company right now," Wallace says. "That would hurt less from a financial standpoint." The fact that the companies' shares haven't been hurt by the recent rumors of regulatory opposition suggests the deal still enjoys strong backing on Wall Street. Monday afternoon, AOL was up 57 cents to $55.82, and Time Warner was up $1.75 to $80.50.