Sales start March 15 at Sprint stores and a day later through Palm's online store.

The shipment news came one day after Palm officials issued a cautious that partly blamed "later-than-expected shipments of the Treo Pro" for a decline in revenues in the third quarter, which ended Feb. 27.

The statement also said that "the challenging economic environment" and reduced demand for Palm's older smartphone products led to its estimate that revenues for the quarter will range from $85 million to $90 million, down from the same quarter a year ago.

CEO Ed Colligan said in the statement, however, that the , built on the new WebOS that was announced in January, "remains on track" for shipment in the first half of this year. He said there has been "extraordinary response" to the Palm Pre and WebOS, which "reaffirms our confidence in our long-term prospects and our ability to reestablish Palm as the leading innovator in the growing smartphone market."

Last October, however, the Pre was months away from being announced, and some analysts were describing Palm's decision to sell the Treo Pro in unlocked mode as a desperation move. One analyst, Phillip Redman of Gartner Inc., said that selling the Treo Pro unlocked "looks like the " for Palm.