The shares of major energy firms plummeted on Monday as oil prices dropped after eight OPEC+ countries agreed to implement crude oil production hikes on Saturday.

The shares of Woodside Energy Group (ASX:WDS) and Santos (ASX:STO) each fell 3% in recent trade.

Saudi Arabia, Russia, Iraq, the UAE, Kuwait, Kazakhstan, Algeria, and Oman will raise production by a total of 411,000 barrels per day in June from their May production levels. OPEC+ consists of the Organization of the Petroleum Exporting Countries members plus other oil-producing countries.