San Francisco-based cryptocurrency exchange Kraken has finalised a deal to buy London trading firm Crypto Facilities.

Kraken said it was one of the industry’s largest deals to date, valued at nine-figures. Though Crypto’s 25-strong team will remain in London, they will all become Kraken employees and expand the US firm's commitment to expanding its European presence.

The crypto derivatives trader was the first regulated entity globally to list futures on popular coins such as bitcoin, ethereum and ripple. Crypto will remain under the oversight of the Financial Conduct Authority after integration.

"It has been our mission to build the most sophisticated, powerful and user friendly cryptocurrency trading platform," said Timo Schlaefer, chief executive and co-founder of Crypto Facilities.

"Teaming up with Kraken allows us to innovate the next generation of products and tremendously boosts the value we are able to provide to our clients."

Crypto Facilities was previously backed by Playfair Ventures, an early investor in Stripe.

“I’m thrilled to welcome the Crypto Facilities team into the Kraken family,” said Kraken chief Jesse Powell.

“We are excited to introduce eligible clients to these industry leading futures and index products. Over the coming months, our teams will continue to enhance and expand these offerings. We’ve got great stuff in store for traders and institutional clients in 2019.”