FORTUNE — The Royal Bank of Scotland RBS is reportedly planning to cut hundreds of U.S. jobs ahead of the implementation of tougher new regulations.

A memo was sent internally Tuesday at RBS outlining plans for the London-based bank to shrink its U.S.-based mortgage-trading business by two-thirds, according to The Financial Times, which cites anonymous sources. The Wall Street Journal adds that RBS will cut as many as 400 jobs stateside across its mortgage and distressed loan businesses as the bank looks to significantly reduce its U.S. assets. The Journal, which also cites anonymous sources, said the cuts will take place over the next 18 months, while the FT puts the timeframe at two years.

RBS is the latest foreign bank to shed U.S. assets and costs after the Federal Reserve said earlier this year that the U.S. operations of foreign financial institutions would be held to the same stricter regulations as domestic banks. Earlier this month, Barclays BCS said it would lay off 7,000 investment bankers before 2016.

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RBS is also planning to spin off its U.S. banking arm, Citizens Financial Group, which filed for an initial public offering earlier this month.

RBS, which currently employs roughly 2,400 people in the U.S., will keep its rates, currency and global transactions businesses intact, according to the Journal. The bank, which has its U.S. headquarters in Stamford, Conn., is still more than 80 percent owned by the British government after receiving government bailouts at the height of the financial crisis.