Crude oil prices turned modestly lower at the opening bell Friday after reports showed the U.S. labor sector is starting to cool down.

The U.S. unemployment rate held steady at 4.9 percent in January, though job growth of 151,000 for January was below the four-week average reported earlier this week. The U.S. Bureau of Labor Statistics said jobs increased in retail and food services, but declined in transportation and mining.

Crude oil prices were volatile for the opening week of February as economic data mixed with evolving reports of potential production talks between the Organization of Petroleum Exporting Countries and non-member states.

Brent crude oil lost nearly a full percent at the open to start the trading day in New York at $34.14 per barrel. West Texas Intermediate, the U.S. benchmark price for crude oil, moved lower by 1.4 percent to start the day at $31.18 per barrel.

U.S. data show the number of long-term unemployed, or those without a job for 27 weeks or more, has shown little movement since June. Extractive industries, those jobs in the oil and gas sector, moved lower in the latest data set from the BLS.

In terms of demand, the federal government said this week U.S. commercial crude oil inventories increased by 7.8 million barrels for the week. Gasoline inventories increased by 5.9 million barrels, and "are well above the upper limit of the average range," the U.S. Energy Information Administration said.

Crude oil prices are lower in part because supplies outweigh demand. Analysis from consultant group Wood Mackenzie finds lower crude oil prices have yet to result in dramatic production declines, suggesting crude oil prices may only move into the low $40s for 2016 on average.