JOHANNESBURG (Reuters) -Shoppers at Checkers supermarkets in South Africa could soon be cruising the aisles with "smart" trolleys that let them know how much money they are spending and include in-built payment terminals, the chain's owner Shoprite said.

Similar high-tech shopping trolleys have been rolled out or piloted in other countries including Chile via Walmart, and the U.S. and Australia through Coles, but this is the first time they are being trialled in South Africa.

The pilot comes as Shoprite's upscale Checkers chain ramps up its challenge to Woolworths for South Africa's mid-to-affluent consumers in the lucrative upmarket retail space.

The two retailers have been investing heavily in sleek store designs, cutting-edge retail technology and premium product lines.

Following initial testing by office employees at a Checkers supermarket in Cape Town from mid-August, 20 of the new trolleys will be made available to customers at two of the chain's stores, Shoprite said in a statement on Wednesday, without saying how much it had invested.

Called the Xpress Trolley, the shopping cart lets shoppers scan items as they go, track a running total on a digital screen and pay directly on the trolley without needing to queue at a check-out. The screen also assists with in-store navigation.

Shoprite said the trial was part of its strategy "to become South Africa's most profitable and seamless omnichannel retailer".