* FTSE hits 3-wk closing low; biggest 1-day fall in 8 mths

* Financial shares retreat on Dubai worries

* Miners weak as commodity prices fall

* LSE faces technical glitch for more than 3 hours

By Harpreet Bhal

LONDON, Nov 26 (Reuters) - Britain's top shares ended at a three-week closing low on Thursday, pressured by hefty falls in the banking sector as concerns over Dubai's ability to pay its debts took a toll on confidence.

The FTSE 100 .FTSE ended down 3.2 percent, or 170.68 points, at 5,194.13, its lowest close since Nov. 6, and losses on the day represented the biggest percentage drop in eight months. The index is still up 50 percent since a low in March.

Earlier in the session, trading on the index was halted for more than three hours mid-morning following a technical glitch at the London Stock Exchange (LSE.L: Quote, Profile, Research). [ID:nGEE5AP1NO]