* Takes $2.3 bln impairment as cuts long-term oil price view
* Q4 net operating loss $1.9 bln vs forecast $2.1 bln profit
* Break-even price is $27 on projects vs $41 last year
* Shares down 1.2 percent, off earlier lows (Adds detail on output, analysts)
By Nerijus Adomaitis and Gwladys Fouche
LONDON/OSLO, Feb 7 (Reuters) - Norway's Statoil plunged to an unexpected loss in the fourth quarter of last year, as it cut its long-term assumptions for the price of oil and took a $2.3 billion impairment charge on the value of its assets as a result.
But the state-controlled company cheered some analysts with a higher than expected production forecast for 2017, with plans to cut another $1 billion in costs and by saying the average break-even price for its new projects had fallen sharply.
"We guess the market will like Statoil's 2017 guidance and probably forgive the major Q4 earnings miss," said Teodor Sveen-Nilsen at Swedbank.
At 0910 GMT, Statoil shares were down 1.2 percent at 154.7 Norwegian crowns, off an earlier low of 153.4 crowns.
Though oil prices have recovered in recent months, helped by output cuts by major producers, they remain well below levels of more than $100 a barrel earlier in the decade.
Statoil said on Tuesday it now expected benchmark Brent crude to reach $75 a barrel in 2020, compared with a previous forecast of $83, and $80 in 2030, compared with $100 before.
Britain's BP said on Tuesday it expected oil prices to remain above $50 a barrel this year, as it also missed fourth-quarter earnings forecasts.
Statoil said it made a net operating loss of $1.9 billion for the quarter, versus an operating profit of $152 million in the same period of 2015 and analysts' average forecast of a $2.1 billion profit.
The company's adjusted operating profit fell to $1.66 billion from $1.78 billion a year earlier, missing analysts' forecast for a rise to $2.27 billion as its international unit's performance fell short of expectations.
However, Swedbank's Sveen-Nilsen said Statoil's guidance suggested its 2017 production would rise 4-5 percent from 2016, compared with his own expectations for flat to up 1 percent.
The company also estimated its average break-even price for new projects by 2022 had fall to $27 a barrel from $41 this time last year.
"This is impressive and a sign that investment activity is rising again," said Carnegie analyst Kjetil Bakken.
Statoil forecast its capital expenditure would rise to $11 billion this year from a downwardly revised $10 billion in 2016, with spending on oil and gas exploration steady at $1.5 billion.
The company added it would cut another $1 billion in costs this year on top of the $3.2 billion it has already cut. It maintained its dividend policy and said it may buy back shares, subject to approval from shareholders.
Statoil shares have gained 31 percent over the past year, outperforming a 24 percent rise in the Stoxx Europe 600 oil and gas sector index. (Additional reporting by Camilla Knudsen and Terje Solsvik in Oslo; Editing by Mark Potter)