NEW YORK, June 3 (Reuters) - The U.S. Federal Reserve's balance sheet grew slightly in the latest week, Fed data released on Thursday showed.
The balance sheet -- a broad gauge of Fed lending to the financial system -- rose to $2.318 trillion in the week ended June 2 from $2.317 trillion the previous week.
After declining early last year, the balance sheet had been accumulating mass amid the U.S. central bank's asset-buying program.
The program, known as quantitative easing, was aimed at broadly holding down borrowing costs and supporting the ailing housing market while the economy recovered from the worst recession in 70 years.
That effort was also led by the Fed's purchases of mortgage-related securities. The Fed ended its purchases of these securities at the end of March but has continued to take delivery on them.
The Fed's holdings of mortgage-backed securities backed by housing finance companies Fannie Mae FNM.N and Freddie Mac FRE.N totaled $1.114 trillion on June 2, up from $1.113 trillion the previous week.
The U.S. central bank's ownership of debt issued by Fannie Mae, Freddie Mac and the Federal Home Loan Bank System was $166.72 billion compared with $167.38 billion a week earlier.
The Fed's direct overnight lending to top-rated banks fell in the week ended June 2. Primary credit via the Fed's discount window averaged $678 million a day compared with $4.32 billion per day in the previous week. (Reporting by Chris Reese; Editing by Leslie Adler)