LONDON, Jan 15 (Reuters) - Britain's top share index slipped back in early trade on Tuesday, just clinging on to the 6,100 level, tracking weaker Asian markets after comments from U.S. Federal Reserve Chairman Ben Bernanke proved mixed.
Bernanke painted a cautiously optimistic outlook for U.S. economic growth but gave no clear hints on when the central bank would start to curb its aggressive bond purchases, despite speculation that it will halt this year.
At 0809 GMT, the FTSE 100 index was down 4.36 points, or 0.1 percent at 6,103.53, having shed 0.2 percent on Monday after hitting a 4-1/2 year peak early in the session, with the index up over 2 percent since the start of 2013.
Burberry Group was the top blue chip gainer, up 6.0 percent as the British luxury brand posted a 9 percent rise in third-quarter underlying revenue, prompting BofA Merrill Lynch to upgrade its rating to "buy" from "neutral".
Negative broker comment weighed on chip designer ARM Holdings, the biggest FTSE 100 faller, down 3.8 percent, with traders citing the influence of a Morgan Stanley downgrade to "equal-weight" on valuation grounds, and an Investec Securities downgrade.
Traders also noted that ARM shares managed modest gains on Monday in spite of big falls by its key supplier Apple on caution over iPhone 5 demand. (Reporting by Jon Hopkins; Editing by Tricia Wright)