Crude oil prices have dropped due to Saudi Arabia and Iran both increasing output.
Front-month Brent crude futures were down 11 cents and traded at $44.37 per barrel, while the US crude futures slipped 12 cents at $42.52 per barrel, Reuters reported.
The fall in prices cancelled out earlier price gains that came due to a weaker dollar, pumping new cash into the market.
Citi told the news agency: "If anyone had a doubt about Saudi Aramco’s ability to use its logistical system and spot sales to increase market share, its recent 730,000 barrel sale of a cargo to a Chinese teapot refiner in Shandong should lay any doubts to rest."
By targeting 500,000bpd in new sales, Saudi Arabia aims to bring its production up to at least 11 million barrels per day, Citi said.
Iran’s oil exports are growing quickly than expected following the lifting of sanctions.
Earlier this month, Bloomberg reported that Iran exported more than two million barrels per day of crude during the first half of April.
According to traders, an concerning Asian gasoline glut also threatened the recent increase in oil prices as refiners flood the market with products that are not required.