The dollar held firm against the euro and yen on Thursday, retaining gains made on the back of Federal Reserve Chairman Alan Greenspan's optimistic comments about the U.S. economy during the previous session. On the second day of his testimony before Congress, Greenspan said on Wednesday that an above-trend pace of growth is sustainable both this year and next, with no apparent threat to price stability. At 0735 GMT, the euro traded down 0.15 percent on the day at $1.2249 , close to Wednesday's low near $1.2200, its weakest versus the greenback in nearly three weeks. The dollar traded flat at 109.76 yen , near Wednesday's one month-high of 110.31. It was a quarter percent higher against the Swiss franc at 1.2518 , also near three-week highs. U.S. weekly jobless claims are due at 1230 GMT, with analysts forecasting 345,000 new filings compared with 349,000 in the prior week. The European Central Bank holds a non-interest rate meeting, with any announcement about other issues to be released at 1230 GMT.|||