If completed, the deal announced last August would clear the way for Richemont's labels to sign up for technology run by luxury e-commerce specialist Farfetch.

The Competition and Markets Authority said it was considering if the anticipated acquisition by Farfetch of a shareholding and certain rights over YOOX Net-A-Porter Group may lead to a "substantial lessening" of competition within any market or markets in Britain.

Richemont, maker of Cartier jewellery and IWC watches has said it expects a 2.7 billion euro ($2.93 billion) writedown related to the agreement in which Farfetch will initially acquire a 47.5% stake, in exchange for over 50 million Farfetch shares.

The deal comes amid a flurry of industry-wide investments in digital services as luxury players shrug off past scepticism and embrace new channels to reach customers, spurred by a fastershift to online consumption during the pandemic.

($1 = 0.9220 euros)

(Reporting by Huw Jones, Editing by Louise Heavens)