Japanese venture capital firm SBI Investment is leading a Series B funding round in bitcoin exchange Kraken.

While the terms of the deal were not disclosed, Kraken said that a "multi-million dollar" investment had been agreed upon with SBI. Kraken did not say when it expected the Series B round to be completed.

"It’s a fantastic first step toward completing Series B, which will ultimately enable us to scale our business worldwide," said Kraken CEO Jesse Powell.

SBI Investment is the venture capital arm of SBI Holdings, an Internet-based financial group that reported an operating revenue of roughly $2bn in 2015. The firm recently announced that it would work with Ripple to establish a new company with a focus on Asian markets.

The announcement comes shortly after Kraken disclosed that it was acquiring New York bitcoin exchange Coinsetter in an undisclosed deal.

Kraken closed a Series A funding round in March 2014, raising $5m in a round led by Hummingbird Ventures, an early-phase venture capital firm.

Disclosure: CoinDesk is a subsidiary of Digital Currency Group, which has an ownership stake in Kraken.