Crude oil (WTI) was down 1.78% to $46.79 per barrel while Brent crude was slipping 1.58% to $49.13 per barrel.
Oil was retreating Monday on reports of growing output in the Middle East. Iraq's energy minister said on Saturday that the country will continue to ramp up production while Saudi Arabia has kept output around record levels in August, Reuters reports.
Earlier in August, speculation that OPEC countries would agree to an output freeze when they meet next month at the International Energy Forum in Algeria helped bolster oil prices.
But the recent output reports dampened that bullish sentiment.
"The market is increasingly likely to discount the outcome of the event, given, even in the instance of a freeze being agreed, compliance will be an issue," Barclays said in a note cited by Reuters.
Additionally, a stronger dollar following speculation of a U.S. rate hike has weighed on oil prices.
Marathon Oil is a Houston-based exploration and production company operating in North America, Europe and Africa.
Separately, TheStreet Ratings objectively rated this stock according to its "risk-adjusted" total return prospect over a 12-month investment horizon. Not based on the news in any given day, the rating may differ from Jim Cramer's view or that of this articles's author.
TheStreet Ratings rated this stock as a "sell" with a ratings score of D.
The company's weaknesses can be seen in multiple areas, such as its weak operating cash flow and disappointing return on equity.
You can view the full analysis from the report here: MRO