Until last week Omnipoint Communications Corp. of Bethesda was a low-profile player in the personal communications business, building a northeastern regional network based on technology that's standard in Europe rather than technologies used by other U.S. cellular and PCS systems.

Now Omnipoint is the bride with the $5 billion dowry, pledged to marry VoiceStream Wireless Corp., which wants to build North America's first nationwide network using that system.

VoiceStream's offer to acquire Omnipoint for cash and stock worth $31.51 a share boosted the company's stock by almost $10 a share. Friday's closing price of a little more than $28 a share discounts the merger offer for the time it'll take to close the deal and the mix of $8 cash and the 0.8 shares of VoiceStream that shareholders will get.

The offer means investors who paid $16 a share when Omnipoint went public in January of 1996 will just about double their money.

Shares of Metrocall Inc. of Alexandria hit 52-week low a week ago then bounced off the bottom to become the week's second-best stock market performer.

The paging company's stock was up 75 cents to $3.12 1/2 after the announcement of two new ventures.

As cellular phone prices continue to fall, paging companies are scrambling to reinvent themselves. Metrocall made two deals, a text-messaging venture with AnswerNet Network and a customized information downloading service in partnership with The Washington Post Co., Gannett Co., MicroStrategy Inc. and Friedman, Billings, Ramsey Group Inc.

The Washington Post-Bloomberg regional stock index, which has been wiggling around in the same range for the last two months, closed down slightly.

On the losing side, America Online Inc. shares dropped $10 as the market continued to debate the value of Internet stocks. AOL announced its biggest investment ever, a $1.5 billion venture into delivering its service by satellite dish, but that did nothing for the stock. Nor has AOL seemed to benefit from analysts' repeated advice that investors ignore lesser Net stocks and put their money into sector starts like AOL.