13,000 And Counting: Cell Stores Multiply Even As Sign-Ups Slow Carriers hope own stores will stay busy hawking next-generation services.(A)(TRENDS & INNOVATIONS)

Byline: MARILYN MUCH

Walk two blocks along 86th Street on New York's Upper East Side and you're likely to find as many stores selling mobile phones as people using them.

Between the diners, drugstores and clothes shops, nine stores of various stripes hawk wireless.

The nation's malls are no different. Mobile phone stores are popping up everywhere.

The six top players -- AT&T Wireless, Sprint PCS, Verizon Wireless, Nextel, Cingular and VoiceStream -- own about 5,000 stores. You can also buy from stores like Best Buy and RadioShack. They push the total to 13,000, and independent sellers add thousands more.

The growth of outlets sets the stage for a shakeout, especially with new user growth slowing. Chains like …