© Reuters. FILE PHOTO: A Bitcoin logo is seen on a cryptocurrency ATM in Santa Monica

STOCKHOLM (Reuters) - Nordea (ST: ) has forbidden all its roughly 31,000 employees from trading in cryptocurrencies such as bitcoin due to high risks, it said on Monday.

The Nordic region's biggest bank said the ban will be imposed from Feb. 28.

"The risks are seen as too high and the protection is insufficient for both the co-workers and the bank," a Nordea spokeswoman told Reuters in an e-mail, adding that employees who currently own cryptocurrencies will not be forced to sell them, although recommended to do so.

Wall Street has taken a cautious approach to digital currencies, which are unregulated and have very volatile trading patterns.

Bank of America Merrill Lynch (N: ) banned clients from investing in one of bitcoin mogul Barry Silbert's top funds last month, according to a memo seen by Reuters.