Philips has struck its first deal to sell lights with built-in technology that can track shoppers as they move through a grocery store, beaming pop-up coupons to their smartphones.

The world's largest maker of lights said France's biggest retailer Carrefour had agreed to try out the system at a large store in Lille, northern France.

Shoppers interested in using the service will need to install a Carrefour mobile software app on their smartphones and opt in.

The LED lights used in the store can then transmit data to smartphones using light pulses not detectable by the human eye, but registered by smartphone cameras.

As a shopper passes by, say, the juice aisle, the app could be used to display coupons or more detailed information about the products on the shelves.

Philips and Carrefour did not provide financial details of the deal.

Reuters