Sterling was also not far from its best ever level against the euro but touched a six-month low against the dollar at $1.6058 before recovering veryslightly. Japanese government bond cash and futures were higher in Tokyo, partly on short covering after finance minister Kiichi Miyazawa said his ministry might have to consider measures to check rises in long-term interest rates. Greenspan, speaking at his twice-yearly Humphrey-Hawkins testimony to congress on the economy and interest rates, told a questioner he had ``concerns'' about the current high values of stocks. He agreed that some gains were due to improvements in business productivity that had enabled the economy to operate at a higher rate without spurring inflation.But revisiting his famous phrase of December 1996, Greenspan added:

``Whether or not it (the market) is gripped by irrational exuberance is an issue that you won't really know for sure, except after the fact.'' But Wall Street, as one US analyst put it, heard his warning and shrugged. The Dow Jones industrials average closed a negligible 8.26 points down, while the Nasdaq index, heavily weighted toward volatile technology stocks,ended 1.39 percent up.