LONDON (Reuters) - Tesco, the world's third-largest retailer, is to install hi-tech screens at its petrol forecourt stores in Britain that scan queuing shoppers so the company can tailor advertising to them.

A deal with Amscreen, owned by entrepreneur and television personality Alan Sugar, will see the "OptimEyes" system rolled out to 450 Tesco petrol forecourts in Britain.

Tesco, which pioneered the tracking of customer behaviour with its Clubcard loyalty card two decades ago, said cameras built into the screens estimate whether a person is male or female and to which one of three age groups they belong.

Relevant adverts are then broadcast to screens in the checkout area based on these factors.

"The ability to tailor content based on time and location means it can be extremely useful and timely for our customers," said Mr Peter Cattell, category director for Tesco petrol stations.

To counter potential criticism from privacy campaigners the retailer stressed the screens do not use eyeball scanners, facial recognition or identify individual customers in any way.

It said no image or picture of customers is recorded or captured and nor is any personal data captured.

Tesco, which trails France's Carrefour and US No. 1 Wal-Mart by annual sales, is 11/2 years into a 1 billion pound (S$2 billion) turnaround plan in its main British market, where it has been losing ground after focusing investment on a rapid expansion overseas.