Vodafone

(VOD) - Get Report

is considering an offer to buy T-Mobile UK, according to a report.

The U.K.'s Vodafone, the world's largest mobile operator by revenue, is exploring an acquisition of T-Mobile UK, which has an estimated enterprise value of 3 billion euros to 4 billion euros ($4.2 billion to $5.6 billion), even though a deal could be blocked by regulators, the

Financial Times

reports.

T-Mobile's parent company

Deutsche Telekom

(DT) - Get Report

has appointed JPMorgan Chase as an adviser, the newspaper reports.

Vodafone declined to comment for the

Financial Times

. But people familiar with the situation said the company was looking into making an offer for T-Mobile UK, or at least setting up a joint venture.

A merger would make Vodafone the No. 1 mobile phone company in the U.K. in terms of market share with 40%, the report says. It now has a market share of 25%, putting it second behind

O2

, which is owned by Spain's

Telefonica

(TEF) - Get Report

.