The Bank of Japan Policy Board in its Jan. 19 meeting rejected the idea of underwriting government bonds on grounds that it would undermine the credibility of the central bank, according to minutes of the meeting released Tuesday.

The nine-member board, headed by BOJ Gov. Masaru Hayami, also expressed opposition to calls from outside the bank to step up the bank's outright purchase of outstanding government bonds, the minutes show.

The January meeting preceded a Feb. 12 meeting in which the bank decided to further ease its monetary policy by guiding down the unsecured overnight call money rate -- a key short-term interest rate -- to a historic low of 0.15 percent and even to near zero if necessary.

For months leading up to the February meeting, the bank had been under mounting pressure from some Diet lawmakers, economists and U.S. financial authorities to stem the recent rise in long-term interest rates by either underwriting government bonds or expanding outright government bond purchases.

The surge in long-term interest rates has been feared to further undermine the nation's economy by discouraging business and household expenditures. At the Jan. 19 meeting, all board members agreed that the bank's underwriting of government bonds is banned by law for good reason, because such activity would undermine the credibility of the BOJ and lead to the loss of fiscal discipline, according to the minutes.

Many members also argued against expanding or reducing the bank's current pace of outright government bond purchases. The members maintained that, if the BOJ actively did so, market participants would react negatively. That, coupled with the fear of loss of fiscal discipline and downgrades in credit ratings, would increase the risk of long-term interest rates rising further, the members argued.

Many members also objected to scaling back outright purchase operations out of fear that such a decision would invite unwelcome market speculation.

At the end of the January meeting, the board voted 7 to 2 to keep its monetary policy unchanged. Nobuyuki Nakahara dissented, saying the bank should show more clearly the bank's determination to prevent deflation. Eiko Shinotsuka argued that the current level of interest rates could be misinterpreted as helping only the banks and not the public, according to the minutes.