Royal Bank of Scotland (RBS) is set to push through job cuts at its US mortgage business as the lender trims costs to avoid regulatory pressure from the Federal Reserve.The UK-based bank will slash about 300 jobs over the next two years in order to meet the Fed's new rules which require higher capital and liquidity levels. The central bank has also imposed tough stress tests on foreign broker dealers with more than $50bn in assets.RBS, which has $85bn of assets in its broker-dealer, has decided to shrink below the threshold in order to get out of being affected by the regulation.The lender will reduce its non-agency mortgage business by two-thirds over two years, people familiar with the matter told the Financial Times. The bank's move comes after building one of the biggest trading floors in the world in Stamford, Connecticut outside New York. RD