The London Stock Exchange’s CEO Will Leave on the Eve of Brexit

London Stock Exchange Group said Thursday that chief executive Xavier Rolet will leave the bourse operator by the end of December 2018, just under a decade after he took the helm at the firm and only three months before the U.K. is scheduled to leave the European Union.

LSE said it would start looking for his successor immediately.

Rolet, 57, who joined the group from Lehman Brothers, said last year that he would leave the group if a merger with Deutsche Boerse went through. However the collapse of the deal in March meant he opted to stay on for longer.

Under the Frenchman’s leadership, the exchange has completed a string of deals including buying up the FTSE Group and clearing house LCH.Clearnet.

Read: London’s House Prices Are Falling at Their Fastest Rate Since the Financial Crisis

But his attempts to make truly transformative deals eluded him. LSE walked away from an attempted takeover of the Toronto stock exchange in 2011 in the face of a rival bid from Canadian banks, while competition regulators thwarted his bid to merge with Deutsche Boerse, the dominant German exchange group.

Rolet took over at LSE from Clara Furse in May 2009, with his banking background making him a popular choice among the exchange’s largest customers. Under his leadership the company’s market value has risen from less than 1 billion pounds ($ 1.3 billion) to almost 14 billion, helped by diversifying into the derivatives, data and index businesses. But the outlook for much of its business is clouded in uncertainty related to Brexit. As things stand, there will be no clear legal basis for LSE’s cross-border businesses after March 31, 2019 – a potentially devastating legal vacuum for the group.

Rolet argued Tuesday that if the U.K. and EU fail to strike a deal on future arrangements by Brexit day, Europe’s capital markets would become much more fragmented and vulnerable to shocks, as well as raising the cost of capital for European companies.

Read: The U.K. Is Too Busy Fighting With Itself to Negotiate a Brexit Deal With the EU

“To those who want to dismantle a system of global regulatory standards that protects taxpayers, we say: ‘Do not diminish systemically important global financial market infrastructure just to make a political point’,” Rolet wrote in an article for the Daily Telegraph.

LSE said in a separate statement on Thursday that group income for the quarter ended September rose 17 percent to 1.66 billion pounds ($ 2.19 billion), with revenue up 14 percent to 486 million pounds as its clearing and FTSE Russell businesses grew strongly.

Thirteen analysts had forecast total income of 477.5 million pounds, according to company provided consensus estimates.