Thursday saw a six-month low in oil prices as investors were concerned about the slowing demand for energy in China and the United States.

By 12:48 p.m. EST (1748 GMT), Brent crude futures had declined 48 cents to $73.82 per barrel. West Texas Intermediate oil futures for the US dropped 33 cents to $69.05. Prices for both benchmarks were at their lowest since late June.

“With the largest global importer of oil (China) shuttering its thirst for crude, pressure remains on prices as the largest producer, the United States, continues with headline output,” John Evans, an analyst at PVM Oil, said.

U.S. output remained near record highs of over 13 million barrels per day, U.S. Energy Information Administration data showed on Wednesday.

U.S. gasoline stocks (USOILG=ECI) rose by 5.4 million barrels last week to 223.6 million barrels, the EIA said, more than quintuple the 1 million barrel build that had been expected.

Concerns about China’s economy also put a lid on oil’s price gains.

Chinese customs data showed that crude oil imports in November fell 9% from a year earlier as high inventory levels, weak economic indicators and slowing orders from independent refiners weakened demand.