Drilling rig builder Sembcorp Marine Ltd said on Monday its second-quarter net profit rose 5.4 percent from a year earlier, helped by stronger performance from its rig building and fixed platform businesses. The Singaporean company reported a net profit for the quarter ended on June 30 of S$131.6 million ($105.57 million), which brings the first-half net profit to S$254 million. The mean full-year net profit forecast stood at S$597 million, based on estimates from 24 analysts, Thomson Reuters data showed.