European Union regulators have asked companies seeking to complete their desired mergers to delay submitting antitrust filings due to the coronavirus outbreak.

That could affect the timelines of agreed deals. Among the biggest is the London Stock Exchange’s proposed acquisition of Refinitiv.

LSE agreed last year to buy the data and analytics firm in a $27 billion deal aimed at offering trading across regions and currencies.

European competition authorities were expected to rule on the deal “around the summer,” an LSE board member said in January.

But on Monday a spokesperson for the European Commission said companies had been encouraged to delay merger notifications until further notice, pointing to “the complexities and disruptions caused by the coronavirus.”

The spokesperson declined to comment on specific deals.

The Commission had adopted “measures to respect the experts’ advice on social distancing,” he said. “This will affect to some extent our current working habits, but the Directorate-General for Competition is prioritizing actions to fulfill its mission and meet legal deadlines.”

LSE said it remained committed to closing the transaction during the second half of 2020, adding that it continued to “engage constructively with the European Commission and other relevant regulators and stakeholders.”

LSE announced the purchase of Refinitiv last August, just 10 months after a consortium led by U.S. asset manager Blackstone completed a leveraged buyout of Refinitiv from Thomson Reuters. Obtaining regulatory approval was expected to be a lengthy process, possibly requiring the sale of some assets.