Britain's competition regulator said on Friday it has cleared Nationwide Building Society's proposed 2.9-billion-pound ($3.75 billion) all-cash deal to buy Virgin Money UK.

The deal, which was announced in March and is expected to close in the fourth quarter, could create the country's second-largest savings and mortgage provider, after Lloyds Banking Group, the owner of Halifax.

The Competition and Markets Authority said it has found that the proposed deal does not give rise to a realistic prospect of a substantial lessening of competition.

($1 = 0.7732 pounds)

(Reporting by Yadarisa Shabong in Bengaluru; Editing by Sherry Jacob-Phillips)