The London Stock Exchange said on Friday it had completed its $27 billion deal to buy data provider Refinitiv as it bulks up into a major financial data provider to compete with Bloomberg.

A beefed-up LSE will also be at the forefront of Britain’s efforts to maintain the City of London as a top global financial centre after Brexit largely cut off the UK’s huge financial sector from its biggest customer, the European Union.

“This transformational transaction brings together two highly complementary global businesses with a shared commitment to an Open Access philosophy, working in partnership with customers,” LSE Group Chief Executive David Schwimmer said in a statement.

The market for financial information has exploded with the advent of computer-driven trading, triggering a flurry of takeovers as companies seek to create one-stop shops to serve clients and get an edge over traditional rivals in supplying data, dubbed the “new oil”.

The European Commission, which oversees competition policy in the 27-nation EU, said earlier this month its antitrust investigation found a number of concerns about the Refinitiv deal but that they would be addressed by “remedies”.

These include the sale of LSE’s Borsa Italiana, which runs the Milan stock exchange and MTS bond trading platform.

Pan-European bourse Euronext has already agreed to buy Borsa Italiana for 4.3 billion euros ($5.2 billion), subject to the Refinitiv takeover getting the green light.

Refinitiv was 45% owned by Thomson Reuters, owner of Reuters News.

The 300-year old LSE faces new challenges on several fronts.

It clears the bulk of euro-denominated interest rate swaps for EU customers from London, but under temporary access to the bloc that ends in June 2022.

Brussels is reviewing whether to grant long-term clearing access, but in the meantime is piling pressure on euro zone banks to shift their derivatives clearing business from the LSE to rivals like Eurex on the continent.

A government-backed review of UK listing rules will make recommendations next month to help London compete better with New York in attracting tech company floats.

But the LSE has already begun facing stiffer competition in listings from rival EU centres like Amsterdam, where the bulk of euro share trading in London moved to on January 4.