Merger partners Orange and T-Mobile filed for European Commission (EC) approval of their proposed British wireless venture on Tuesday, as the companies’ rivals and consumer groups in the United Kingdom (UK) called on Great Britain’s Office of Fair Trading (OFT) to request transfer of merger review to the UK. Announced in November, the proposed 50-50 joint venture would leapfrog current market leader O2 as the largest mobile phone operator in the UK with 28.4 million customers and a market share of 37%. The combined entity would also control more than 84% of available 1800 MHz band spectrum that is earmarked in the UK for advanced, high-speed wireless services. The filing of merger documents with the EC triggers the start of the EC’s review timetable, under which the EC is required to hand down its initial ruling on February 15. On that date, the EC may approve the deal or launch an in-depth investigation that would take up to 90 days to complete. Meanwhile, the OFT confirmed Tuesday that it is considering “whether to make a request to the EC for the proposed joint venture to be referred to the OFT for review.” Voicing concern about the impact of the proposed merger on competition, O2 and other opponents have urged the OET to investigate the transaction. O2 and 3UK, the smallest of Great Britain’s five current wireless operators, have also called on the joint venture to relinquish some of the 1800 MHz spectrum that they will amass through the merger on grounds that permitting one company to control such a large amount of 1800 MHz spectrum will “distort the market.” Since current European Union merger regulations went into effect in 2004, the OFT has made four requests for the EC to take over merger review. The final decision on which regulatory body will conduct that review rests with the EC.