Daniel Akerson, the aggressive chief executive who led Nextel Communications Inc. from near-bankruptcy to become a powerful force in the cellular industry, is stepping down from the company's top post.

The news came as Reston-based Nextel reported one of its strongest financial quarters ever, although the company is still not profitable.

Nextel President Timothy Donahue will replace Akerson, who will become co-chair of Eagle River Investments LLC on Aug. 1. Akerson will share that job with cellular pioneer Craig McCaw, who formed the company in 1994 to invest in telecommunications companies. Eagle River holds McCaw's interests in Nextel, Nextlink and Teledesic.

Akerson will continue to serve as chairman of Nextel until Jan. 1. McCaw will become chairman of the Nextel board at that time. Akerson said he will remain active in Nextel's operations and as a board member but had accomplished most of the goals he set upon his arrival almost four years ago.

Since Akerson's arrival, Nextel has focused on business customers and has led the industry with offerings such as not charging roaming fees, and one-second rounding of call time. Last month it introduced an Internet-ready phone, ahead of its rivals.

"I think I'm more of a builder than a manager," Akerson said yesterday in a telephone interview. Akerson, a former MCI president, said his decision to leave was partly personal, partly professional, and that in addition to being co-chair at Eagle River he would be a significant investor.

In May, talks involving a possible merger of Nextel with MCI WorldCom fell through after the two sides failed to agree on a price. Some people have speculated that Akerson had been disappointed in that failure, but he said the failed talks had nothing to do with his decision to move on.

Later that month, Microsoft Corp. surprised the industry by announcing its plans to buy a 4.25 percent stake in Nextel, a deal that made Microsoft the Web portal, or gateway, for Nextel's Internet phone users. Some local telecommunications executives are also surprised that McCaw has tapped Akerson to join him at Eagle. "Craig and Dan have had some conflict over Dan's management style in the past," said one executive who spoke on the condition of anonymity. "He's been somewhat concerned with the way Dan treats people." However, the executive, who is familiar with the situation, said, "Craig believes Dan can make him lots of money."

"We're highly confident in Tim's ability to be a very effective CEO. . . . He and Dan have been a powerful combination for Nextel but there comes a time when a guy is ready to take the reigns," said Bob Ratliffe, spokesman for Eagle River and a longtime associate of McCaw's.

Ratliffe said McCaw has no negative feelings toward Akerson, who has admitted in the past that he can be intense and that the people who bother him most are those who want to be loved.

"Do Dan and Craig have the same management style? No, they don't," Ratliffe said. "Dan's tough and strong," he said, noting that McCaw is "softspoken, kind -- not to say that Dan's not kind."

Donahue is known for a more gregarious, open-door style of management.

Yesterday Nextel reported a second-quarter net loss of $267.7 million compared with $358.7 million a year ago. Revenue increased 88 percent to $793.1 million.

Staff writer John Schwartz contributed to this report.