Handspring, of Mountain View, California, said its "Trade up to Treo" program lets owners of its personal digital assistants (PDAs) or other wireless devices, including those made by Palm Inc.PALM.O , Research In Motion Ltd.RIMM.O and others, to get a $100 rebate on the Treo 180 model.

Handspring's Treo debuted earlier this year to critical fanfare, but sales have been disappointing. The company recently said it will redouble its efforts to market and sell Treo, including further training at retail stores. More powerful models are expected to be released later this year.

The Treo retails at $499 with the simultaneous activation of a new cellular service agreement.

A Handspring spokesman on Tuesday said the rebate plan would hopefully inspire sales from current PDA owners, who already understand and value the devices, in hopes of spurring increased word-of-mouth.

Handspring owners can obtain the rebate via the company's Web site. Customers who own another handheld device will receive the same discount through the mail. A complete list of qualifying products can be found on Handspring's Web site, http://www.handspring.com.

The program runs through June 2 and applies to Treo devices purchased either with or without service activation.

Shares of Handspring closed on Tuesday off 11 cents, or about 5 percent, at $1.96, its lowest levels in seven months. The shares have suffered in recent weeks, accelerated by its April 15 report of a third-quarter loss on slumping revenues, its forecast that fourth-quarter revenues would fall short of estimates and the resignation of its chief financial officer.