First Data Corp. has begun selling a portable and wireless point-of-sale terminal for mobile merchants.

The FD400 terminal is battery-powered, letting merchants take payments even when they are not near a power supply. The pocket-sized device can, however, link up through a wireless cellular connection, allowing data to be transmitted wherever a wireless provider has such coverage. It can also store transactions to be uploaded later if it is used in an area without reliable wireless data coverage.

"For merchants whose business is not always in a location with Internet or dial-up connections, this terminal really solves their connectivity dilemma," Russell Bird, a First Data senior vice president, said in a press release Monday.

Other companies also offer payment acceptance through devices and services designed for use in remote locations. In May Intuit Inc. launched its GoPayment service, which works with mobile phones, to appeal to businesses that take most of their transactions in the field, and BServ Inc. of San Francisco bought the assets of Commerciant LP, a maker of card-acceptance devices that can be used in environments such as airplanes.