Bell, Boyd & Lloyd, a midsize, Chicago-rooted law firm, is losing groups of attorneys as it grapples with the question of how to expand in a megafirm market.

The departures grew partly out of disenchantment with the firm’s approach to growth under a management team that so far has sidestepped a merger, said some former Bell Boyd attorneys who declined to comment on the record. Although the firm has considered various partners, it hasn’t found a good fit, Bell Boyd Chairman John “Jack” McCarthy said.