Investment in the oil and gas industry will see a tentative recovery in 2017 after an “unprecedented contraction” in 2016 and 2015 in face of stubbornly low energy prices, the International Energy Agency said in a report on Tuesday.

The IEA said upstream oil and gas investment — such as in exploration and production facilities — fell 26 percent in 2016 in nominal terms to $434 billion (380 billion euros), similar to the decline seen 2015.

The IEA, an intergovernmental group set up to ensure the reliable supply of energy, released the report at the World Petroleum Congress in Istanbul, where energy bosses are debating the consequences of the dramatic plunge in oil prices.

Participants have warned that the sharply lower investment levels seen in the last two years risk compromising security of supply for consumers, as discoveries and development of new oilfields falter.

According to the IEA, investment in oil and gas in 2016 was little more than “half the peak level of 2014, when oil prices started to fall sharply.”

It described the fall in investment in 2015 and 2016 totalling $345 billion as “an unprecedented contraction” and was partly due to reduced drilling activity.

But asking whether there could now be “light at the end of the tunnel”, it said that the oil industry has reacted to the price crisis by drastically ramping up efficiency.

This improved the financial health of companies and their cash flow, creating the chance of a slight recovery in investment in 2017.

It estimated, on the basis of company announcements, that global oil and gas upstream investment in 2017 is set to increase by almost six percent to just below $460 billion in nominal terms.

But it added: “Many of the largest oil and gas companies are still implementing a cautious approach in scaling up their spending plans”.

It said that firms would be less ambitious in their planning were oil to fail to recover to above $50 a barrel.