Britain's antitrust regulator said on Tuesday it had started a review of supermarkets' loyalty pricing, as the watchdog considers whether it is fair that cheaper prices are available only to members.

The Competition and Markets Authority had announced plans in November to review loyalty pricing schemes such as Tesco's Clubcard and Sainsbury's Nectar.

The regulator said on Tuesday it had begun talks with supermarkets and will publish an update on its work in July. It expects to finish the review by the end of the year. (Reporting by Yadarisa Shabong in Bengaluru; Editing by Maju Samuel)