The Bank of Japan has ended a monetary policy meeting by tweaking its lavish stimulus program to encourage more corporate investment.

This week, the U.S. central bank raised its key interest rate by a quarter percentage point, signaling confidence in the recovery, but Japan's is still struggling to re-ignite growth after years of stagnation.

The BOJ is pumping tens of trillions of yen (trillions of dollars) a year into the economy by buying up government bonds and other assets.

The central bank said Friday that it will expand purchases of shares in exchange traded funds for companies that increase hiring and investment. That would increase its 3 trillion yen ($24 billion) in purchases of ETFs by 300 trillion yen ($2.4 billion).