Mercer is acquiring a health and welfare practice in the Southeast.

Mercer is buying that practice, and a defined contribution advisory practice, from Mahoney & Associates, Springfield, Mass. The practices Mercer acquired are in Fort Lauderdale, Fla.

Mercer, a human resources consulting and outsourcing subsidiary of Marsh & McLennan Companies, Inc., New York (NYSE: MMC), hopes to complete the deal by Aug. 31. The price was not disclosed.

Completing the Mahoney deal will make Mercer the largest health and benefits broker in the Miami-Fort Lauderdale insurance brokerage market — the ninth largest brokerage market in the United States.

The acquisition also will expand the distribution capabilities of Mercer DC advisors, which provides consulting, advisory and brokerage services for small and midsize defined contribution retirement plans and profit-sharing plans.

Mahoney & Associates has been selling health and welfare plans, qualified retirement plans, executive compensation and benefits programs, and related advisory services.

Willliam Mahoney Jr., the company’s president and founder, will be keeping the company’s individual insurance practice, a Mercer spokesman says.

Mercer is part of the same corporate group that includes Marsh, Guy Carpenter and Oliver Wyman. The Mahoney & Associates deal is the second acquisition announced by a Marsh & McLennan subsidiary in the past eight days.

Another Marsh & McLennan unit, Marsh & McLennan Agency L.L.C., said last week that it was acquiring Prescott Pailet Benefits L.P., Dallas, as part of an ongoing effort to create a national distribution network by buying regional hub agencies.

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