The net profit of Keppel Corporation, the world\'s largest oil rig builder, in the third quarter fell 15 percent year on year to 346 million Singapore dollars (284 million U.S. dollars), the company announced on Thursday. This is mainly due to lower margins from the company\'s offshore and marine sector. But the net profit was still above market expectations. The company said it remained upbeat about the growth opportunities in the offshore and marine sector. Choo Chiau Beng, chief executive officer of the company, said the spending in the sector remained buoyant, \"supported by sustained Brent oil prices of above 100 U.S. dollars per barrel.\" Its third quarter revenue was up 19 percent year on year at 3. 22 billion Singapore dollars. But the rise in costs outpaced the revenue growth. For the nine months ended September, its net profit climbed 47 percent to 1.62 billion Singapore dollars (1.33 billion U.S. dollars). The company\'s third-quarter revenue came in at 3.22 billion Singapore dollars (2.64 billion U.S. dollars), up 19 percent year on year. The net profit for Keppel\'s offshore and marine division in the third quarter fell 29 percent year on year to 241 million Singapore dollars (198 million U.S. dollars).