Washington (AFP) - The Federal Reserve on Friday said it had paid a record $98.7 billion in profits to the Treasury in 2014, most of it earned from its stimulus for the US economy.

Under Fed policy, its 12 regional banks must pay to the federal government what is left of earnings after certain items, such as operating expenses and dividend payments, are deducted.

Last year's payment widely eclipsed the central bank's previous record of $88.4 billion in 2012.

The Federal Reserve banking system had net income of roughly $101.5 billion in 2014, according to preliminary estimates, the Fed said.

Most of the income came from $115.9 billion in interest generated by financial assets it held, including Treasury bonds and mortgage-backed securities.

The $98.7 billion sent to the Treasury last year was twice as much as the Fed paid in 2008. The collapse of Lehman Brothers in September that year triggered the financial crisis that spurred the Fed into a bond-purchase program, or quantitative easing (QE), two months later, pumping cash into the stricken economy.

The Fed's asset purchases, part of its strategy to fight the 2008-2009 financial crisis and recession, have swollen its balance sheet to some $4.5 trillion in assets, compared with $900 billion before the crisis.

After six years and three separate rounds of QE, the Fed ended its bond purchases in October.