BP PLC (BP) reported that its Thunder Horse Gulf of Mexico project faces another setback, as a metallurgical failure will delay first production for at least 18 months pending the rebuilding of all production equipment on the sea bed, according to a Dow Jones Newswire report. The offshore oil and gas platform's new startup date will be mid-2008, a year and a half later than the previous estimate of early 2007, the London-based energy major said. The mammoth Thunder Horse field, the largest oil discovery in the deepwater Gulf of Mexico, has been plagued by delays since the platform was left listing after the passage of Hurricane Dennis in 2005.