Petro is the name of a supranational currency proposed by Venezuela

Venezuela

Venezuela , officially called the Bolivarian Republic of Venezuela , is a tropical country on the northern coast of South America. It borders Colombia to the west, Guyana to the east, and Brazil to the south...

n President Hugo Chavez

Hugo Chávez

Hugo Rafael Chávez Frías is the 56th and current President of Venezuela, having held that position since 1999. He was formerly the leader of the Fifth Republic Movement political party from its foundation in 1997 until 2007, when he became the leader of the United Socialist Party of Venezuela...

 at the second South America-Arab League Summit in Qatar

Qatar

Qatar , also known as the State of Qatar or locally Dawlat Qaṭar, is a sovereign Arab state, located in the Middle East, occupying the small Qatar Peninsula on the northeasterly coast of the much larger Arabian Peninsula. Its sole land border is with Saudi Arabia to the south, with the rest of its...

 in 2009, to face the instability that the generation of fiat currency has caused the world economy.

The petro-currency would be backed by the huge oil reserves of oil producing countries. It would supersede the US dollar as the global reserve currency

Reserve currency

A reserve currency, or anchor currency, is a currency that is held in significant quantities by many governments and institutions as part of their foreign exchange reserves...

.