BARACK OBAMA'S odds of winning the US Presidential Election have been shortened by William Hill for the first time since Sarah Palin became John McCain's running mate and transformed the betting.

Hills have reduced Obama's odds from 4/6 to 4/7 favourite and lengthened McCain from 11/10 to 5/4.

Palin's campaign has been dogged by negative media reports of her teenage daughter's illegitimate pregnancy, and her homophobic "pray away the gay" views.

"Perhaps the Palin factor boost has levelled out now, as money has begun to come in again for Obama to win after a couple of weeks during which the large majority of cash has been for McCain" said Hill's spokesman Graham Sharpe. "Obama had drifted out to the longest odds he'd been since winning the candidacy, while McCain's had been shortening consistently."