Anticipating a U.K. financial-services regulation that could require banks to record the mobile-phone conversations of their traders and sales personnel, British mobile operators are introducing services that allow corporate clients to record and retain communications on work-issued cellphones.

Telecommunications giant Vodafone Group PLC on Thursday formally rolled out a recording service for clients in Western Europe after testing it at a number of financial-services firms for about a year. Orange, the mobile operator owned by France Télécom SA, launched a similar service earlier this month.

Both use an application on the handset to route all inbound and outbound mobile calls.