When VoiceStream Wireless Corp. agreed to buy Bethesda's Omnipoint Corp. back in June, a lot of investors figured the ride was over for Omnipoint.

The cellular phone company was one of the Washington region's best-performing stocks in the first half of the year. But after the merger agreement sent the stock soaring, analysts started rolling back their ratings.

Raymond James & Co. cut Omnipoint to "neutral" and Robinson-Humphrey Co. slashed the stock to "short-term market perform."

Oh, if only the market had done as well as Omnipoint since then.

The stock was the region's No. 1 performing investment in the third quarter of the year, up 97 percent from $28.31 1/4 to $55.87 1/2 at the close of Thursday's trading. Omnipoint is also the No. 1 performing stock so far this year, up 500 percent since Dec. 31, when you could have bought the shares for $9.31 1/4.

In contrast, the Nasdaq Stock Market -- where Omnipoint shares trade -- is up 7.5 percent for the quarter and 25.2 percent for the year, which is the best performance of any major market index. The Dow Jones industrial average is up 12.6 percent for the year, but lost 5.4 percent last quarter; the Standard & Poor's 500-stock index is up 4.4 percent for the year after losing 6.6 percent last quarter; and the Washington Post-Bloomberg regional stock index is off 3.7 percent for the year after falling 6.5 percent over the past three months.

The regional index represents stocks of 213 companies based in the District, Maryland and Virginia. Only 65 of those stocks gained during the third quarter. One was unchanged. The rest fell.

Omnipoint not only blasted past those paltry benchmarks but also defied the conventional wisdom that stocks of companies that are taken over usually jump immediately after the merger is announced, then float listlessly until the deal is consummated.

Omnipoint's purchaser turned out to be one of Wall Street's favorite telecom stocks at a time when telecom stocks generally are highly regarded. (Among the region's other big winners this year is Nextel Communications Inc. of Reston, whose stock gained 35 percent last quarter and is up 187 percent for the year.)

VoiceStream, whose offices are in the suburbs of Seattle, was spun off in May from Western Wireless Corp., which until then had operated a pair of cellular phone networks using two different, competing technologies. VoiceStream stock ended the quarter at $61.71 7/8 a share, up 201 percent since the spinoff in May and up 117 percent in the past quarter.

When VoiceStream's stock escalates, Omnipoint shares go up with it because the merger involves a stock swap as well as cash. Omnipoint shareholders will collect $8 a share in cash when the companies combine later this year and will also get 0.825 of a share of VoiceStream for each of their Omnipoint shares.

VoiceStream stock has been moving because the company has launched an acquisition strategy designed to create the first nationwide wireless phone system using the technology that is standard in Europe, known as GSM.

After agreeing to buy Omnipoint's East Coast network in May, VoiceStream two weeks ago bought Aerial Communications Inc. of Chicago, which has a big network in the Midwest. Analysts say it's only a matter of time until VoiceStream buys or builds more GSM systems so it can become a national player.

Conspicuously absent from this quarter's list of the winners among regional stocks is what is supposed to be the hottest category of all: Internet stocks.

The region's biggest Internet names -- America Online Inc. and Network Solutions Inc. -- have recovered some of the losses they took during what is becoming the annual Net stock summer slump, but AOL ended up down 5 percent for the quarter while Network Solutions was up 16 percent for the period.

Two recent Internet initial public offerings have been hot, but the stocks haven't been public long enough to qualify for the official ratings. Shares of Proxicom Inc., the Reston creator of Internet sites, have blasted from $13 a share to $58.50 at the close of business Thursday since that company went public in April. And shares of AppNet Systems Inc., of Bethesda, is also in the buiness of creating and managing Web sites, jumped from $12 to $27.37 1/2 since the IPO on June 18.

Another IPO of what might be considered an Internet company would make the list of losers for the quarter if companies that have gone public since the first of the year were counted. After a spectacular debut under the name Realty Information Group, shares of what is now CoStar Group Inc. of Bethesda shot from $9 to $48.50. It closed Thursday at $22.50 a share, down from $43.50 at the beginning of the quarter.

In part, the initial run-up was fueled by the impression that investors were buying an Internet stock because the company sells real estate data over the Net. But analysts apparently have decided that real estate is the real business of CoStar, and real estate is not one of Wall Street's favorites this year.

The price was also knocked down by a big secondary stock offering in which a number of insiders cashed in some of their shares.

While Internet stocks lost their glow, biotech and related stocks are back.

The quarter's big winners include Human Genome Sciences, up 87 percent; MedImmune Inc., up 47 percent; Fuisz Technologies, up 91 percent -- but still down for the year -- and U.S. China Industrial Exchange.

Human Genome Sciences, which is mapping the human genetic code, and MedImmune, which has reached the stage of marketing drugs, are the blue chips of biotech and the industry's only local stocks with a strong national following.

Fuisz, whose original business of creating drugs that dissolve instantly has been supplemented by an online pharmacy, recovered from a deep dive when it received a takeover bid from Biovail Corp. International of Toronto. The firm recently acquired more than 50 percent of Fuisz's stock for $7 a share.

U.S. China Industrial Exchange operates medical clinics and hospitals in China and exports medical supplies to that country. Long lost among the biomedical penny stocks, the company has dramatically increased its sales and visibility this year.

Penny stocks are excluded from the quarterly rankings because issues selling for less than $3 tend to be extremely volatile and their wild swings are as apt to be produced by trading frenzies as by meaningful developments.

The raw data for the quarterly rankings showed eight of the 10 worst losers for the quarter were stocks below the $3 cutoff, most of them long-suffering companies with tiny revenues.

But one of the big penny stock losers was Metrocall, the giant Alexandria paging company that has 5.8 million customers nationwide. Three years ago, Metrocall was a $20 stock, but the cell-phone boom that is making Nextel and Omnipoint big winners is killing the pager business. Metrocall's shares lost half their value during the quarter, closing at an all-time low of $1.25 a share. The final insult for investors came two weeks ago when Metrocall lost its national Nasdaq listing because of the slumping stock price.

UPS AND DOWNS

Conspicuous by their absence from the third quarter's big winners are a Washington area staple: Internet stocks.

WINNERS

Company: Omnipoint Corp.

Sept. 30: $55.87 1/2

Third quarter: 93%

YTD: +475%

Company: Fuisz Technology

Sept. 30: 6.31 1/4

Third quarter: 91%

YTD: - 51%

Company: U.S. China Industrial Exchange

Sept. 30: 12.43 3/4

Third quarter: 88%

YTD: 352%

Company: Human Genome Sciences

Sept. 30: 73.75

Third quarter: 87%

YTD: 108%

Company: Deltek Systems

Sept. 30: 16.37 1/2

Third quarter: 66%

YTD: - 1%

Company: MedImmune Inc.

Sept. 30: 99.65 5/8

Third quarter: 47%

YTD: 109%

Company: Nextel Communications

Sept. 30: 67.81 1/4

Third quarter: 35%

YTD: 184%

Company: LCC International

Sept. 30: 6.06 1/4

Third quarter: 35%

YTD: 60%

Company: Transaction Network Services

Sept. 30: 39.25

Third quarter: 34%

YTD: 93%

Company: Integral Systems

Sept. 30: 28.75

Third quarter: 26%

YTD: 41%

LOSERS

Company: VCampus Corp.

Sept. 30: $3.12 1/2

Third quarter: - 57%

YTD: - 47%

Company: Crown Central Petroleum/A

Sept. 30: 6.00

Third quarter: - 49%

YTD: - 15%

Company: Sinclair Broad Group

Sept. 30: 9.06 1/4

Third quarter: - 45%

YTD: - 54%

Company: CyberCash

Sept. 30: 7.31 3/4

Third quarter: - 43%

YTD: - 50%

Company: Excalibur Technology

Sept. 30: 8.25

Third quarter: - 42%

YTD: - 31%

SOURCE: Bloomberg News