The UK competition watchdog has given preliminary approval to telco BT’s bid to acquire the country’s largest mobile operator, EE. This makes is highly likely that the acquisition will go ahead, creating a quad play leader in one of Europe’s most competitive markets, and returning BT as a significant mobile player for the first time since it spun off its cellular arm, now Telefonica O2. Telefonica’s own prospects of offloading that subsidiary in a sale to Hutchison Whampoa, which also owns 3UK, are less clear. National and European antitrust regulators have traditionally been wary of deals which reduce the number of mobile operators in a market. Telefonica will hope that its deal will be assessed in the context of broader…