On Wednesday, Great Britain’s Office of Fair Trading (OFT) petitioned the European Commission (EC) for rights to review the proposed merger of T-Mobile and Orange’s mobile phone operations in the United Kingdom (UK), warning that “the joint venture threatens significantly to affect competition in mobile telecommunications in the U.K.” Announced last fall, the combination of Orange and T-Mobile, which rank respectively as the third- and fourth-largest wireless carriers in the U.K., would leapfrog current market leader O2 as the largest mobile telephony provider in the nation with 29.5 million subscribers and a 37% share of the U.K. market. The transaction would also reduce the number of national U.K. wireless carriers from four to three. Although T-Mobile and Orange have already filed merger documents with the EC to trigger a formal EC review process that is slated for completion on February 15, the OFT told the EC that was seeking authority to examine the proposed joint venture “with a view to deciding whether it should be referred to the [U.K.] Competition Commission for an in-depth investigation.” Wednesday’s development is expected to postpone the transaction at least through March 1—the deadline by which the EC is required to act on the OFT petition. If the EC grants the request, much longer delays are expected, especially if the OFT refers the transaction to the Competition Commission. Asserting that “a referral of the case is not needed,” a spokesman for Deutsche Telekom, the parent of T-Mobile, proclaimed, “we strongly believe that the transaction is pro-competitive and are therefore confident that we will be able to resolve the remaining concerns.”