As AT&T Wireless ( AWE) packs for its Cingular journey, investors are fretting that many subscribers won't come along for the ride.

AT&T Wireless, the No. 3 U.S. cell-phone service provider, has spent the last year stumbling in spite of the industry's record-breaking growth spurt. The company's many mishaps -- ranging from poor service quality and software glitches to the onset of number portability -- finally drove it this winter into the arms of a highly motivated buyer, No. 2 wireless power Cingular.

But Wall Street analysts say the bleeding is far from over at AT&T Wireless. In fact, some expect the Redmond, Wash., company to suffer an almost unheard-of setback when it reports earnings on April 28. These skeptics estimate that AT&T Wireless will lose between 50,000 and 200,000 customers in its first quarter ended last month.

A decline wouldn't just end a decade of consistent growth at AT&T Wireless and brand the company as the only major player losing subscribers. Some bears speculate that a growing torrent of customer losses could even force Cingular to re-evaluate the terms of its $41 billion bid for the company, which is due to close at year-end.

"I think people have some doubts about the timing, and some possibility of the merger not getting done," says Deutsche Bank analyst Viktor Shvets, who has a hold rating on AT&T Wireless. Deutsche Bank has been an underwriter for the company.

Wishy Washy

The prospect of a Cingular-AT&T Wireless breakup appears remote. Shvets thinks the deal will go through, barring "something extraordinary." Other analysts agree it would take nothing short of a disaster to derail the deal.

Even so, judging by AT&T Wireless' stock price, investors haven't exactly given the pact a full vote of confidence.

On Feb. 17, Cingular, a joint venture of SBC ( SBC) and BellSouth ( BLS), agreed to pay $15 in cash for each share of AT&T Wireless. Typically, an all-cash bid from a financially sound company such as Cingular would push shares of the acquisition target close to the merger price. But AT&T Wireless shares never exceeded $14.10 and have mostly traded in the high $13 range. On Thursday, AT&T Wireless slipped 8 cents to $13.64.

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