Bank of Japan policymakers, concerned about a serious deterioration in corporate and household sentiment after the March 11 earthquake and tsunami, decided on a step to ease monetary conditions, minutes released by the central bank showed Tuesday.

The nine-member Policy Board agreed that "Japan's economic activity could be adversely affected through possible deterioration in the sentiment of firms and households," the minutes of its March 14 meeting said.

The board voted to double the BOJ's asset purchase fund to \10 trillion, mainly to support fundraising by companies, with one member opposing the move.