UPDATE: Fitch could downgrade UK banks today, says Sky News

The banks tumbled lower late Thursday morning - despite rising earlier on - on the back of reports that Fitch could cut ratings across sector.Barclays was the heaviest faller, losing over 4% as of 11:48, while HSBC and Lloyds were also under the cosh."The credit ratings agency Fitch is poised to deliver further grim news for Britain's banks by warning of a sector-wide downgrade later today, I can exclusively reveal," writes Mark Kleinman in his blog for Sky News.Fitch is understood to have told the country's major high street lenders to expect a statement about the review for downgrade after the stock market closes today. Kleinman adds that, "It's possible that the statement will be brought forward now that I have disclosed the development."AB