Richard Gary has a few words of advice for firms that are smitten with merger fever: Don’t take marriage lightly. As one of the chief architects of the 1998 union that created Thelen Reid & Priest, he speaks from experience. “It has been very difficult,”says Gary, who is chairman of the new 404-lawyer firm. “We have had tough issues to deal with,”like melding practice groups on opposite sides of the country. Knowing what he does now, would the firms still have merged? Absolutely, he replies: “[But] we would go into it with our eyes open even wider.”

Gary’s prenuptial firm — San Francisco’s Thelen, Marrin, Johnson & Bridges — faced a dilemma in the spring of 1997 that probably sounds familiar to many midsize firms today. It needed to grow — substantially and quickly — to hold on to its clients and to remain competitive. The solution, the firm decided, was to merge.