PARIS/LONDON (Reuters) - Euronext ENX.PA has joined a growing list of exchanges citing Brexit to win a reprieve from a new rule aimed at promoting competition in clearing services for derivatives trades.

FILE PHOTO: Company stock price information is displayed on screens as they hang above the Paris stock exchange, operated by Euronext NV, in La Defense business district in Paris, France, December 14, 2016. REUTERS/Benoit Tessier

The pan-European exchange becomes the fourth exchange this week to be granted a waiver until July 2020 from having to comply with an “open access” rule under a European Union law known as Markets in Financial Instruments Directive II or MiFID II, introduced on Wednesday.

Under the new system aimed at increasing competition, an exchange would have to make available data from a derivatives transaction to any clearing house.

At present, investors are effectively locked into using an exchange’s clearer of choice, typically owned in-house. Clearing ensures a trade is completed even if one side of the deal goes bust.

Euronext operates stock and derivatives trading platforms in Paris, Brussels, Amsterdam and Lisbon.

Regulators in France, Belgium and Portugal have granted an open access waiver in respect of derivatives, Euronext told Reuters. The exchange is still waiting for the outcome of a waiver request to regulators in the Netherlands.

Euronext said the waivers would ensure orderly markets as Britain, the region’s biggest derivatives trading centre, leaves the EU next year.

“We need a resolution of the bigger picture before we move into any open access activities in respect of exchange traded derivatives,” Euronext said.

Regulators in Germany and Britain this week granted the same 11th-hour waiver to Deutsche Boerse DB1Gn.DE in Frankfurt, and ICE Futures Europe ICE.N and London Metal Exchange 0388.HK.

UK regulators have said they granted waivers in the interests of keeping markets orderly as other aspects of MiFID II, a sweeping reform, are digested by markets.

Deutsche Boerse has said a waiver was needed due to legal uncertainty created by Brexit.

Euronext uses LCH to clear its transactions.

LCH is majority owned by the London Stock Exchange LSE.L which is one of the region's biggest supporters of open access. It has not asked regulators for a waiver.

“Our open access approach will continue, working in partnership with our customers to promote greater choice, transparency and innovation in financial markets, in order to reduce risk and maximise capital and operational efficiencies,” an LSE spokeswoman said.

The EU’s markets regulator, the European Securities and Markets Authority, said on Wednesday that all waivers from open access will be “one-offs”.