U.S. Fed's balance sheet up, MBS tops $1 trln

NEW YORK Feb 18 (Reuters) - The U.S. Federal Reserve's balance sheet expanded in the latest week, Fed data released on Thursday showed.

The Fed's balance sheet -- a broad gauge of its lending to the financial system -- rose to $2.259 trillion in the week ended Feb. 17 from $2.239 trillion in the previous week.

Borrowing at the Fed's discount window averaged $87.73 billion per day in the week ended Feb 17, up a shade from $87.70 billion a day in the week ended Feb. 10.

Fed holdings of agency debt totaled $165.59 billion on Feb. 17 versus $164.95 billion on Feb. 10.

Fed holdings of agency mortgage-backed securities rose to $1.026 trillion in the week ended Feb. 17 from $976.87 billion in the previous week.

(Reporting by Burton Frierson, Editing by Chizu Nomiyama)