* Says 2009 will be a challenging year
* Results in line with median estimate of analysts
* Order book at S$10.8 billion in December 2008
(Adds derived Q4 earnings, analyst estimates)
SINGAPORE, Jan 22 (Reuters) - Singapore's Keppel Corp, the world's largest offshore oil rig builder, posted a 6.9 percent rise in full-year net profit, and said on Thursday 2009 would be a challenging year.
The conglomerate earned S$1.097 billion ($735 million) last year, up from S$1.026 billion in 2007. The results were in line with the median estimate of S$1.072 billion of 17 analysts polled by Reuters Knowledge.
Revenue for the full year rose 13 percent to S$11.8 billion, of which 72 percent was from the offshore and marine division. Keppel is also involved in property and oil refining.
Keppel did not report separate results for the fourth quarter. However, by deducting reported earnings for the first nine months of 2008 from the full-year total, its net profit for the period would have been about S$264 million.
"By the end of 2008, the global economic situation had deteriorated so far that the world tanked into a recession," the company said in a statement.
"There is little doubt that Keppel will be impacted by the global crisis."
Keppel Corp and rival Sembcorp Marine benefited from the jump in oil exploration in recent years as prices soared to record highs, but oil prices slid from near $100 a barrel early in the quarter to about $45 by end-2008.
Keppel's order book stood at S$10.8 billion in December 2008, down from S$13 billion at the end of the third quarter due to order cancellations and a lack of new orders.
Keppel said earlier this month it has agreed to cancel a $405 million rig contract deal with Scorpion Offshore, after warning in November that three clients may cancel orders worth S$1.2 billion.
Shares of Keppel Corp fell about 45 percent in the October-December quarter, underperforming a 25 percent drop in the broader Straits Times Index and a 44 percent drop in Sembcorp Marine over the same period. (Reporting by Kevin Lim and Neil Chatterjee; Editing by Andrew Macdonald)