Higher U.S. oil reserve data contributed to a Friday decline in the price for West Texas Intermediate crude oil, ignoring good news from the labor market.

West Texas Intermediate, the U.S. price benchmark, lost more than 40 cents early Friday to trade at $66.37 per barrel for the January contract.

Crude oil prices have continued a steady downward trend at least since June in response to more oil production from U.S. shale and weak economic performance elsewhere in the world.

The U.S. Energy Information Administration said Friday domestic proved oil reserves have passed the 36 billion barrel mark for the first time since 1975, a time when U.S. markets were coping with the effects of an export embargo from Arab members of the Organization of Petroleum Exporting Countries.

An OPEC decision last week to keep production levels static was seen as an effort to dampen the growth of the U.S. shale oil industry, which is in part behind the steady rise in reserves and production. In its monthly report on rig activity, oil services company Baker Hughes said the U.S. oil sector was holding steady.

More oil on the market tends to lead to lower prices because supplies outweigh demand. Signs of recovery in the U.S. labor market, which could signal stronger future demand, did little to influence crude oil prices, however.

The U.S. labor market gained more jobs in November, though wages are still behind the curve.

Globally, Baker Hughes finds rig activity increasing for November despite the price for Brent crude oil, the global benchmark price, shedding value.

Brent for January delivery shed 42 cents early Friday to trade at $69.22 per barrel.