(For more stories on the Japanese economy, click )

TOKYO, March 14 (Reuters) - The Bank of Japan on Monday injected a hefty 7 trillion yen ($85 billion) into the money market in a same-day market operation aimed at soothing market jitters after a massive earthquake and tsunami hit northeastern Japan.

This was the central bank's first so-called same-day operation since last May, when the Greek debt crisis roiled the global financial markets.

BOJ Governor Masaaki Shirakawa said on Sunday that the central bank would provide huge amounts of liquidity to the banking system on Monday, reinforcing the bank's determination to keep markets stable in the wake of the disaster. ($1 = 81.915 Japanese Yen) (Reporting by Leika Kihara and Rie Ishiguro; Editing by Edmund Klamann)