Sienna Miller popped up a the afterparty for the New York City premiere of her film Factory Girl donning a much buzzed outfit featuring black shorts and tights. Now retailers in Britain believe that the twenty-five year old actress may have sparked a fashion trend.

British retailer George said sales of black control pants shoot through the roof in their store following flicks of Sienna in the get-up.

More 230 per cent more photos of the “Pant’s Over Tights” look shot up compared to the last week.

“Our customers have said knickers to that and are buying them by the shed load – they love them,” said a George representative.

Fashionistas say Si Si was actually wearing “micro shorts-” which are predicted to be an immense hit during the Summer of 2007.