The past few months have been trying for companies and countries which produce oil and other commodities, the prices of which have slumped as demand has slowed in China - the motor of global growth in recent years - casting a cloud over the global economic recovery.
Repsol, which acquired Canada's energy firm Talisman last year, added that without the provision, the group would have made a net profit of €1.86 billion last year - a nine-percent rise from 2014.
"This result specifically measures the performance of the business units and demonstrates the company's strength and resilience in the face of adverse situations such as the current low oil and gas prices," it said in a statement.
Shares in the oil giant - which had already warned the markets of its 2015 loss last month - rose 3.15 percent to 8.85 euros mid-morning on Thursday.
Separately, the group announced it had agreed to sell its offshore wind power business in Britain to China's SDIC Power for €238 million.