TOKYO - Tokyo stocks firmed 0.16 percent in cautious trade Thursday morning, with traders concerned about Greece’s ability to implement reforms following this week’s bailout deal.

The Nikkei 225 index at the Tokyo Stock Exchange rose 15.63 points to 9,569.63 by the break. The Topix index of all first-section issues was up 0.08 percent, or 0.69 points, at 826.09.

Investors were taking a breather after recent gains amid a lack of fresh buying cues, Daiwa Securities senior market analyst Yumi Nishimura told Dow Jones Newswires.

But she also said the Japanese unit “staying firm above the 80-yen mark is providing some support.”

The dollar eased slightly to 80.18 yen in early Tokyo trade, from 80.29 overnight in New York. The greenback on Wednesday broke the 80-yen barrier for the first time in more than six months.

The euro was trading at $1.3247 and 106.22 yen, slightly down from $1.3252 and 106.41. Traders have grown nervous over whether Greece will be able to carry out the swingeing cuts and reforms necessary to implement the multi-billion-dollar rescue deal agreed on Tuesday morning after marathon talks in Brussels.

The worries also weighed on US stocks, with the Dow Jones Industrial Average ending 0.21 percent, or 27.02 points, lower at 12,938.67.

International ratings agency Fitch added to the pressure when it said on Wednesday a Greek default was “highly likely” and it cut its credit rating by two notches from “CCC” to “C”.

The move means Athens is now at the bottom of the speculative grades and just one step above formal default.

Also, eurozone private sector activity fell back in February after returning to growth in January, a survey showed, adding to concerns the region is flirting with recession.

Mazda Motor fell 6.8 percent to 137 yen on fears over a share glut after the company said it will raise up to 162.8 billion yen in a major new share issue. Panasonic edged down 0.27 percent to 724 yen after Standard & Poor’s cut its credit rating.