As part of a billion-dollar IT infrastructure improvement program, Kmart Corp. on Wednesday unveiled a three-part technology rollout that will expand its use of self-service checkout, move lines with roaming handheld devices, and use bar codes to track inventory on the shelves.

The 300 NCR Corp. self-service checkout units already in use will expand to 600 stores, a Kmart representative says, while bar code readers from Symbol Technologies Inc. will be used to tally the purchases of consumers while they're standing in line. Customers will get a printed total, which they can then hand to the cashier, pay, and be on their way. The same bar-code readers will be used by employees to read the labels on the shelves when a product is out of stock, to determine delivery status, and to produce daily reports of what needs to be restocked.

Also debuting this month is an Ateb Inc. interactive voice-response system that will be available at all 1,589 Kmart pharmacies, so customers can reduce their waiting time by calling 24 hours a day to renew prescriptions and leave messages for the pharmacist.

The company says that as many as 40% of customers are using self-service checkout in some stores.