The blue-chip index ended a volatile session down 0.1%, while the midcap index <.FTMC> recorded a 0.3% fall as a profit warning from PageGroup hit the recruitment sector.

Worries over trade policy and a weak global economy "continue to weigh on the U.S. economic outlook" and the Federal Reserve was ready to "act as appropriate", Powell said in prepared remarks to a congressional committee.

The downbeat tone brought back hopes that the central back of the world's biggest economy would cut interest rates for the first time in a decade at its policy meeting this month.

That hit the greenback, thereby pressuring shares in FTSE 100's more internationally exposed stocks, including HSBC, British American Tobacco and spirits company Diageo.

"The Fed chair seems to have well and truly left the door open to a rate cut in July," Markets.com analyst Neil Wilson said. However, doubts remain over whether this will be first of several, or an "insurance" cut designed to keep markets on an even keel, he added.

"The testimony didn't appear to tell us anything about what the Fed is thinking longer term"

Software firm Micro Focus saw its biggest one-day fall since March 2018 with a 15.1% slump, a day after reporting a larger-than-expected decline in licence revenue in its first half.

However, losses were contained thanks to strength in miners <.FTNMX1770> as metal prices rose on signs of improvement in the U.S.-China trade talks.

Recruitment firm PageGroup skidded 15.1% on its worst day in three years after warning that uncertainty related to Brexit and the China-U.S. trade war would eat into its operating profit.

That knocked shares in rivals Hays and Robert Walters by 5.8% and 7.3% respectively.

Pub operator J D Wetherspoon was at the other end of the spectrum, ending 3% higher after reporting stronger comparable sales for the 10 weeks to July 7 and keeping its full-year expectations untouched.

Among small caps fashion group Superdry shed 2%, having earlier fallen as much as 10% after posting results showing a 130 million pound charge for poorly performing stores pushed it into an annual loss.

(Reporting by Muvija M and Shashwat Awasthi in Bengaluru, Editing by William Maclean and Jan Harvey)

By Muvija M