The college's board of trustees reached the decision during its quarterly meeting over the weekend, College President James Wright and Chair of the Board of Trustees William Neukom said.
The college currently does not hold stock in any of the companies, they said.
"The practical effect of this would be that our various fund managers," Wright said, "will be instructed not to purchase in these companies."
Earlier this year, Harvard University decided to sell an estimated $4.4 million stake in PetroChina, whose parent company is tied to the Sudanese government.
A campus group, the Darfur Action Group, said it collected signatures from over a quarter of the student body calling for Dartmouth's action.
The Darfur Action Group's Niral Shah, a Dartmouth sophomore, said the college's move represents "a screen against all future investments" in companies tied to the Sudan regime.
"There's a lot of frustration on campus about the lack of meaningful response to the violence in Darfur on the part of the international community," said Janet Smith, a student organizer.
Darfur Action Group identified the six companies as ABB, Greater Nile Petroleum Operating Co. Ltd., PetroChina Co. Ltd., Sudanese White Nile Petroleum Co., Petronas and Sinopec.
Divestiture of state pension funds has been approved in several states.
The United Nations estimates that 180,000 people have died in conflicts between the government and rebel groups, mainly through famine and disease. Several million more have either fled into neighboring Chad or been displaced inside Sudan.