UK banks fall on media report of potential tax increase in October budget

** Shares of major UK banks down following a Guardian report that Britain's finance minister John Healey plans to tax lenders in the October 28 budget

** Report says tax is aimed at keeping deficit-reduction plans on track after impact of Iran war on public finances

** NatWest NWG.L and Lloyds LLOY.L down about 2% each, making them the top drags in the FTSE 100 .FTSE, which was down 0.1%

** Shares of Barclays BARC.L edge 0.5% lower