Norwegian oil giant Statoil on Wednesday again slashed its investment forecast for this year as dropping oil prices and writedowns led to weaker-than-expected third quarter earnings.

The group reported a net loss of 2.8 billion kroner (299 million euros, $329.1 million) during the quarter, which was an improvement on the 4.8-billion-kroner loss it registered in the same period a year ago owing to a vast cost savings programme.

"I am pleased with the way we are taking costs down, but the continued low prices in the third quarter demonstrates that we must continue to chase further cost efficiencies," chief executive Eldar Saetre said in a statement.

In addition to falling oil prices, Statoil's earnings were weighed down by large provisions for asset depreciation and legal disputes.

On the operational level, earnings declined more than anticipated.

Adjusted earnings -- the reference figure for the market which excludes exceptional items -- plunged to 16.7 billion kroner, from 30.9 billion a year earlier.

That was 800 million kroner lower than analysts had forecast, and the Statoil share price was down by 1.96 percent in late morning trade on the Oslo stock exchange.

Statoil, which is 67-percent owned by the Norwegian state, has had to tighten its belt recently, like its competitors. It said its investments for this year would amount to $16.5 billion, down from the previously forecasted $17.5 billion.

Statoil has placed a lot of hope in the massive Johan Sverdrup oil field in the North Sea, which is expected to begin operations in late 2019 and whose development costs have been reduced by seven percent.

But the group has postponed until the second half of 2018 the start of operations on the Aasta Hansteen field in Norway and the Mariner field in Britain. They had been expected to open in 2017.

The delays are bad news for the Norwegian economy, which relies heavily on the oil sector.

On a positive note, the company said it expects a three-percent rise in its production this year. Production rose by four percent in the third quarter, totalling 1.909 million barrels of oil equivalent per day, allowing it to compensate somewhat for the 37-percent drop in the oil price when measured in kroner.