UPDATE 3-Seadrill Q4 hit by writeoffs, sees earnings rising

* Q4 EBITDA $226 mln, vs $258 mln forecast

* Posts net loss of $739 mln due to big writedowns

* Expects strong earnings growth ahead

* Shares up 0.6 percent

(Adds details, quotes)

OSLO, Feb 26 (Reuters) - Norwegian oil rig company Seadrill Ltd (SDRL.OL) reported fourth-quarter losses stemming from hefty writedowns announced earlier, but said it expected strong earnings growth in coming quarters.

Seadrill said on Thursday one-off charges and financial losses of $810 million, announced on Monday, dragged it to a net loss of $739 million in the three months to end-December.

Excluding non-recurring items, earnings before interest, tax, depreciation and amortisation (EBITDA) rose 42 percent to to $226 million at the Bermuda-registered company, which is controlled by Norwegian shipping tycoon John Fredriksen.

The result excluding one-offs lagged analysts' average expectation for EBITDA of $258 million in a Reuters poll, compiled before Seadrill announced the writeoffs on Feb. 23.

Estimates ranged between $205 million and $294 million.

Seadrill shares closed up 0.6 percent at 52.50 crowns before the report, valuing the company at about $3.05 billion.

The company took writedowns of $615 million on the value of shareholdings in Pride International (PDE.N), Scorpion Offshore (SCORE.OL) and SapuraCrest Bhd (SCRS.KL), as announced earlier.

It also took mark-to-market losses of $160 million on interest rate swaps and a loss of $35 million related to total return swap agreements on its own shares, Seadrill said.

"The significant drop in oil and gas prices from the record levels experienced in early 2008 together with the ongoing credit crunch are impacting the activity levels in most rig segments."

The company, which has 32 drilling units and 11 more under construction, said several planned drilling programmes seemed less likely in the current market environment.

"The board is very confident in its outlook for the company's operation and expects a strong increase in earnings over the next quarters," Seadrill said in a statement.

EBITDA GROWTH THROUGH 2012

Chief executive Alf Thorkildsen said in a conference call for analysts that the company expected compounded annual EBITDA growth of 33 percent from 2008-12.

Thorkildsen said the deepwater business remained promising, but the jack-up rig market was the most uncertain.

"The deepwater market depends on the long-term view of the oil companies, and so far that is holding up and creating a reasonable market for these units," he said.

"I think that the long-term future is clearly in the deep water," he said. "That is where the large reserves and the replacement opportunities for the oil companies lie, so I think you will see continued interest in those prospects."

Seadrill did not announce a dividend but said it would work to restore a payout in 2009, adding: "In the medium to long term, a high dividend is a key part of Seadrill's business strategy".

Seadrill said it had got over $2 billion in various financing facilities since October and was fully financed in early 2009 and comfortable with its debt covenants. (Additional reporting by Richard Solem) (Reporting by John Acher and Joergen Frich; Editing by Dan Lalor and Andrew Macdonald)