TOKYO The Bank of Japan likely continued to intervene stealthily in the currency market during the previous week even after its record yen-selling intervention last Monday, market sources told Reuters.
They said trading evidence showed the central bank probably continued to intervene, albeit in small amounts, since Monday, when Japan spent an estimated 7.7 trillion yen ($98.5 billion), a daily record for intervention, to curb the yen's strength.
The dollar has since been mostly supported above 78 yen and traders said there were persistent bids around 77.80 yen last week, which helped prop up the dollar.
The yen has risen as the greenback has come under pressure from expectations of more easing by the Federal Reserve while the euro has been bruised by the debt crisis.
The U.S. currency was last trading around 78.13 yen, about 3.7 percent above a record low of 75.31 yen hit on October 31 just before Japanese authorities stepped into the market.
That contrasts with Japan's previous unilateral intervention on August 4, when the dollar jumped more than 4 percent only to completely erase gains in just three days.
Finance Minister Jun Azumi told parliament on Wednesday that it was not the time to review the impact of intervention -- a comment some market players took to mean that he was still keen to intervene.
Japanese authorities said last Monday's intervention was prompted by the need to take measures against speculative market moves, with Finance Minister Azumi saying authorities would continue to intervene until they were satisfied.
But officials have since declined to comment on whether they are continuing to intervene.
Bank of Japan money market data since then does not show any large unusual payment from the government to banks after Monday, suggesting any additional intervention would have been small in size.
If confirmed, Monday's intervention would surpass the record 4.5 trillion yen of yen-selling conducted on August 4.
Full details of Japan's intervention in this quarter will be published in mid-February. ($1 = 78.180 Japanese Yen)
(Reporting by Tokyo Markets Team; Editing by Edwina Gibbs and Joseph Radford)