The continuing consolidation in the mobile phone business made one local cellular phone company the week's biggest winner in the stock market, but knocked another onto the losers list.

Shares of Omnipoint Corp., the top-performing local stock this year, jumped more than $8 a share after Aerial Communications Inc. announced plans to be acquired by VoiceStream Wireless Corp., which already is buying Omnipoint.

Omnipoint and VoiceStream made a powerful marriage, but adding Aerial to the family moves VoiceStream into the mainstream of wireless communications.

Nextel Communications Inc. stock dropped almost $10 after the Aerial-VoiceStream merger was announced because investors feared Nextel might get left out of the action. There had been speculation that Nextel might be bought by MCI WorldCom Inc., but that company has been talking to Sprint Corp. about a merger, it was disclosed last week.

America Online Inc. reversed its drift downward, jumping $10 a share Friday after AOL dodged the first bullet in an expected Internet price war. There had been speculation that Microsoft Corp. would cut the price of its MSN Internet service, forcing AOL to follow suit. Instead MSN raised its rates by $2 a month. Even if AOL doesn't follow MSN upward, the threat of price cuts has eased, analysts calculated.

There were few other significant winners among mid-Atlantic stocks last week as the Nasdaq Stock Market and the Dow Jones industrial average took big hits. The Washington Post-Bloomberg regional stock index, which has been weak since early July, fell 3 percent during the week.

The regional index, which represents stocks of companies in the District, Maryland and Virginia, is down more than 9 percent from its summer peak. All the spring and summer gains have been erased and the benchmark for local stocks is back where it was in April.

Most regional stocks fell during the week. Hardest hit was Dynex Capital Inc., a Richmond-based mortgage investment company, which announced that it would not be able to pay its regular dividend, knocking 40 percent off its stock price.