A view of the Exxon Mobil refinery in Baytown, Texas September 15, 2008. REUTERS/Jessica Rinaldi Standard and Poor's credit rating services downgraded debt of ExxonMobil from the top rating of 'AAA' to 'AA+' on Tuesday.

"We believe Exxon Mobil's credit measures will be weak for our expectations for a 'AAA' rating due, in part, to low commodity prices, high reinvestment requirements, and large dividend payments," said the release from S&P.

"The company's debt level has more than doubled in recent years, reflecting high capital spending on major projects in a high commodity price environment and dividends and share repurchases that substantially exceeded internally generated cash flow."

The credit rating agency did maintain a stable outlook on the debt, however, citing "responsible capital stewardship" and the company's industry-leading position.

Exxon could receive an upgrade back to AAA, said the release if the company pays down more debt as oil prices rise.

"We could consider raising the ratings if management demonstrated commitment to financial policies consistent with our expectations for a minimal financial risk," wrote the S&P. "These include using discretionary cash flow to reduce debt significantly when oil and gas prices recover from current levels, and commitment to maintaining very conservative credit measures..."

This is a huge move, Exxon has held it's 'AAA' since 1930 according to a report from Bloomberg. Also, this moves Exxon from an elite class. Before the downgrade the company was one of only three firms that held a 'AAA' rating, now only Microsoft and Johnson & Johnson are in that category.

Additionally, the downgrade comes as the oil industry is experiencing a serious down turn. Low prices have lead to plummeting profits, a deterioration in credit conditions and a major increase in bankruptcies for the sector.