Los Angeles is now home to the largest full-service employee benefits firm in the United States.

At least that’s the description MullinTBG is applying to itself, following its creation last month with the merger of Los Angeles-based Mullin Consulting Inc. and TBG Financial, a Los Angeles subsidiary of Columbus, Ohio-based Nationwide Financial Services Inc.

The combined former rivals will administer more than 400 nonqualified benefit plans with $15 billion in total assets. The merged company plans to up the ante by competing against mutual fund giant Fidelity Investments through an expansion of its retirement and advisory services to high-level executives.

Mike Shute, the former chief executive of TBG Financial who assumed the role of chief executive of MullinTBG, said the company is trying to anticipate the needs of retiring Baby Boomers.

“Nobody is really offering a service that anticipates the needs of executives and top employees as they retire,” he said. “We can’t be a parts supplier; we need to be giving people the whole package.”

Peter Mullin, the founder and chairman of Mullin Consulting, will assume the chairmanship of the combined company.