When Daniel F. Akerson gave up the chief executive's job at Reston's Nextel Communications Inc. in July, a clause in his contract kicked in that forced him to cash in options on a million shares of Nextel stock.

The options produced a $51 million payoff for Akerson, who is credited with turning Nextel from an also-ran in the mobile-phone business into one of the three companies offering nationwide service.

But between the time Akerson sold his shares and the time the transaction showed up on Securities and Exchange Commission reports last week, Nextel stock jumped $20 a share.

Leaving $20 million on the table will make even the wealthiest executive wince, but whatever disappointment Akerson feels has to be softened somewhat by the comfort of knowing that he still has 3.2 million shares, worth more than $200 million at Friday's $75.18 3/4 closing price for Nextel stock.

A quarter of a billion dollars' worth of stock for three years' work is the kind of incentive compensation that often raises the hackles of shareholders. But Nextel stockholders have no more reason to bemoan Akerson's paycheck than he has to fret about the money he didn't earn on his options.

Since Akerson and his team of managers took over Nextel in the spring of 1996, the company's stock has climbed from about $16 a share to an all-time high of $72 earlier this month. Including some new shares that were issued, the market value of Nextel's stock has multiplied to nearly $30 billion from about $5 billion.

Akerson will continue to benefit from Nextel's growth because he will become co-chairman of Eagle River Investments, a private company founded by cellular pioneer Craig McCaw. Eagle River is Nextel's biggest stockholder, and Akerson put much of the money he made on his Nextel stock into Eagle River.

While Internet entrepreneurs have gained the glory in Washington business in the past few years, the time period also has been great for telecommunications companies, the region's first homegrown industry.

Nextel and the region's other big mobile-phone company, Omnipoint Corp. of Bethesda, have been two of the region's hottest technology stocks this year. Omnipoint's stock also hit an all-time high this month, closing at $53.93 3/4 Tuesday. It closed Friday at $51.87 1/2.

"The reason these have been so strong is entirely related to the growth we've had in the industry," said Brad Williams, an analyst at Legg Mason Inc. "You've had very strong subscriber growth, very good usage metrics. People are out there using their phones a lot more, becoming a lot more dependent on them."

But managements of the two local players also deserve a lot of credit because they have found ways to prosper in a crowded and highly competitive field.

On the air less than two years, Omnipoint made up for being a latecomer by concentrating on the pre-paid cellular phone market. Analysts say about half Omnipoint's customers buy phones with pre-paid service, many because their credit isn't good enough to qualify for conventional service. Pre-paid cellular service has long been popular in other countries, and it is beginning to take off in the United States.

Omnipoint's stock has doubled in the last three months since it agreed to merge with VoiceStream Wireless Corp. of Bellevue, Wash. Omnipoint and VoiceStream use a different technology than other mobile phones, a system that is standard in Europe but unusual in the United States. Their phones can be used in London and Paris, but not in large parts of the United States, including the Washington area.

The combined company plans to build out a national network to match those now offered by AT&T Corp., Sprint Corp. and Nextel.

Nextel became a national player in the mobile phones by developing technology to make phone calls on radio bands that had originally been designated for use by taxi dispatchers, tow trucks and other two-way radio users.

Nextel still caters to business users, letting others fight for the consumer market where price wars now are the primary method of attracting customers.

Building on its roots, Nextel's phones have a walkie-talkie feature that lets customers talk to others on their personal network at the push of a button. I first appreciated this feature last summer when I found the general contractor building an addition on my house had passed out Nextel phones to all his subscontractors. At the push of the button, the missing electrician could be found.

About half the calls on Nextel's network are made within work groups. The average customer has five phones and uses them more than 400 minutes a month, generating a much higher average bill than conventional cellular services.

Nextel now is testing the first mobile phones with built-in Internet connections, capable of showing text from some World Wide Web sites on their little display screens. The service will be available early next year, and Wall Street analysts say it could make Nextel phones even more attractive to business customers for confirming orders, checking inventories and receiving e-mails.

Some people who study the future of telecommunications say it's too early to tell. "This is a time of experimentation in wireless phones and data," said Jane Zweig of Herschel Shosteck Associates Ltd., a wireless communications research firm in Silver Spring.

"It's going to be tricky for all the operators promoting phones with Internet access," she said. "The reality of the delivery may not be what end users think about when they talk about the Internet."

Zweig said cellular phone companies are searching for new ways to make money because basic calling has become a low-profit commodity business. Generating more revenue per customer is the name of the game.

Nextel's strategy for boosting its already-high revenue per customer is to stick to the business users who have shown they are willing to pay for services that enhance their productivity.

Omnipoint, on the other hand, may have trouble selling luxuries like e-mail to customers whose finances are so iffy that they need to pay in advance for their cellular phone. Pre-paid customers tend to use their phones less. Further, competition in that market is increasing; even AT&T has started offering pre-paid cellular service.

CAPTION: Dial for Dollars (This graphic was not available)