OSLO (Reuters) - Bermuda-based offshore oil driller Seadrill said it saw an increasingly tight ultra-deepwater rig market and planned for additional newbuild units as it reported second-quarter earnings roughly in line with forecasts.“The board is increasingly confident that our target of a $4 billion EBITDA can be reached when the new units are in operation,” it said.The Oslo-listed firm posted an EBIDTA of $634 million in the April-June period, compared with a $579 million profit in the same period last year, while the mean forecast in a Reuters poll was for a $639 million profit.Net profit came in at $554 million, above expectations of $475 million.“These are good results from Seadrill, as usual,” said Anders Hagen, analyst at ABG Sundal Collier. “The company exceeds expectations with a positive deviation in operating income, with good contracts hidden in the numbers.”Shares in Seadrill were up 0.3 percent at 0820, roughly unchanged from before the report was published, while the Oslo benchmark index was up 0.6 percent.The company has said it aims to almost double its earnings before interest, taxes, depreciations and amortisation (EBITDA) to $4 billion on an annual basis by late 2015.Seadrill, which operates and leases a 46-strong fleet of drillships and rigs, has been on a rig spending spree in recent years, awaiting delivery of 18 new ships and rigs - eight of which have already been chartered out on long-term contracts - as it aims to keep up with fast-paced developments in oil exploration.“The board believes that the units under construction will not be sufficient to meet the expected incremental global demand,” it said. “Consequently, Seadrill is actively negotiating for additional newbuild units.”