Asia stocks mixed after Europe credit downgrade BANGKOK (AP) - Asian stock markets were mixed Tuesday after ratings agency Moody's slapped credit downgrades on six European Union countries due to the region's weak economic outlook and uncertain attempts to implement reforms. Benchmark oil hovered above $100 per barrel while the dollar rose against the euro and the yen. Japan's Nikkei 225 index, reversing early morning losses, rose 0.6 percent to 9,064.90. The gains came as the Bank of Japan, following a policy meeting, announced it would buy more government bonds while keeping short-term interest rates near zero to boost the economy. The U.S. dollar rose to a three-week high against the yen after the central bank's announcement, Kyodo News agency said. That helped Japan's exporters, whose earnings have been trampled by a strong home currency. Toyota Motor Corp. jumped by 1.8 percent and Suzuki Motor Corp. was 2 percent higher. Canon Inc. gained 1.5 percent. Elsewhere, Hong Kong's Hang Seng was unchanged at 20,886.69 while South Korea's Kospi was marginally lower at 2,004.65. Australia's S&P/ASX 200 lost 1 percent to 4,243.90. Government debt ratings can play a major role in countries' borrowing costs because a lower rating often means countries must pay higher interest rates on their bonds to attract investors. Moody's downgrades came amid efforts to prevent recession-mired Greece from a chaotic default on its massive debts. Tom Kaan of Louis Capital Markets in Hong Kong said the Greece factor was starting to diminish in importance as tensions in the Middle East moved to the forefront after bomb attacks on Israeli diplomatic targets that the Jewish state blamed on Iran. There are fears that an escalation of hostilities between Israel and Iran could set off a conflict across the region and send oil prices skyrocketing. "The way things are going, it's not going to be good for oil prices or for global ," Kaan said. On Monday, stocks rose on Wall Street after investors received news of the parliamentary vote in Athens. Benchmark oil for March delivery was down 35 cents to $100.56 per barrel in electronic trading on the New York Mercantile Exchange. In currency trading, the euro fell to $1.3162 from $1.3202 in New York. The dollar rose to 77.86 yen from 77.61 yen.