The Bank of Japan (BOJ) pledged to increase purchases of exchange-traded funds (ETF) but kept interest rates steady at the close of its two-day meeting on Friday, confounding market expectations of hefty stimulus.

In an eagerly-awaited decision, the central bank said it would ramp up ETF purchases so that their amount outstanding will rise at an annual pace of 6 trillion yen ($56.7 billion), from 3.3 trillion yen previously.