This story has been updated.

About a fourth of the employees at McBee Strategic — the lobbying, communications and advisory firm acquired by D.C. law firm Wiley Rein last month — have left or plan to leave following the announcement that McBee founder Steve McBee was leaving to join an energy company.

The departures include 16 employees, including five senior people at the executive vice president level, in addition to mid-level and junior staffers and associates. Two of the 16 were McBee’s assistants who left with him. Together, they represent 27 percent of the 60 employees who worked at McBee at the time McBee announced his departure to the company in November.

However, the firm has kept the vast majority — nine out of 11 — of McBee’s top revenue generators, Wiley Rein leaders said.

McBee Strategic founder Steve McBee in 2013. (Jeffrey MacMillan/Capital Business)

The Wiley acquisition was prompted by McBee’s decision to leave his firm to work for the New Jersey-based power company NRG Energy. He started Dec. 1 as the president and chief executive of NRG Home, the new clean-energy business unit within NRG Energy.

Josh Lahey and Matt Johnson, former McBee executive vice presidents for advertising and lobbying, respectively, joined lobbying powerhouse Podesta in recent weeks. Colin Hayes, former McBee executive vice president specializing in energy policy, returned to the Senate Committee on Energy and Natural Resources in December, according to his LinkedIn profile. Ray Glendening, former vice president of innovation, will leave to join Direct Impact later this month, Glendening confirmed Thursday. Direct Impact is a mobile grassroots campaigning firm and a subsidiary of public relations firm Burson-Marsteller, which is owned by the global conglomerate WPP.

Lobbyist Rob Hobart, an executive vice president who led McBee’s government capital group, and Pete Cohn, a vice president in communications, are also departing.

McBee Strategic, founded in 2002 by McBee, a former Democratic aide, was one of K Street’s fastest-growing success stories. Just a year before its acquisition, the firm was touting its growing digital communications division, which Glendening was hired to lead. The firm earned $10.4 million in lobbying fees in 2013, and pulled in additional revenue from other business units: a government capital group that helps companies compete for government grants and contracts, a business advisory unit, and a research and analytics group.

John Procter, who leads McBee’s international communications division, declined to comment on how the departures would affect the firm’s overall business. The firm is aggressively interviewing candidates to replace those who have left, and last month hired Noe Garcia as executive vice president in charge of the firm’s state-level grassroots advocacy work.

Former McBee employees, who spoke on the condition they not be named so as not to jeopardize relationships, said that despite the exits, many of the core contacts for McBee’s lobbying and communications clients remain at the firm. The former employees expressed confidence that McBee would continue to run successfully as part of Wiley Rein, but that the firm would look very different compared to when it operated independently.

Wiley Rein has about 275 attorneys, all in the District and Northern Virginia, and is known primarily for its telecommunications practice.