Energy company ConocoPhillips, which has already cut 1,000 jobs this year, says it will eliminate around 1,810 more positions following a plunge that took oil prices to their lowest levels in years. The company said Tuesday it is eliminating 10 percent of its workforce. The biggest proportion of the job cuts will be in North America. ConocoPhillips plans to eliminate more than 500 jobs in Houston, where it is based. In a statement, ConocoPhillips said it's making the cuts because the energy industry is in a "dramatic downturn." ConocoPhillips had 18,100 employees on June 30. Oil prices have plunged because of a supply glut that built up as production increased and growth in the global economy slowed. The health of China's economy, the second-largest in the world, is a dominant concern. In response to falling oil prices almost all energy companies have either cut spending on exploration or cut jobs, often both, and many have seen big drops in their stock prices. Oil and gas and drilling services companies have said they'll cut tens of thousands of positions. The biggest oilfield service company, Schlumberger, is eliminating 20,000 jobs.