PROVIDENCE — The decision to withdraw the state’s pension investments from companies that overtly or indirectly aid in genocide in Sudan’s Darfur region “has already borne fruit,” state General Treasurer Frank T. Caprio said at a signing ceremony for the divestment bill yesterday.

Rhode Island was the 19th state to approve divestment, and Caprio said that trend helped to persuade Rolls Royce PLC to stop doing business in Sudan. “They got the message,” Caprio said.

Rolls Royce, a U.K.-based multinational corporation, had furnished diesel engines and support for Sudan’s oil industry. Oil revenues, in turn, financed the government-backed militias propagating the genocide.

“I think we all have been deeply moved and disturbed by the horrific images of the genocide in Darfur,” Governor Carcieri said at yesterday’s signing, which was ceremonial. The governor signed the bill — sponsored by Rep. Joseph S. Almeida, D-Providence, in the House and Sen. Rhoda E. Perry, also D-Providence, in the Senate — into law on June 22, the day before the end of the legislative session.

“This is about hitting the Sudanese government where it hurts most, which is in their pocketbooks,” Carcieri said.

A similar bill died last year after former treasurer Paul J. Tavares expressed reservations, saying he supported its spirit but feared it might hurt the performance of the pension fund. But Caprio, who was elected last fall, made the issue a top priority, urging passage early in this year’s session.

The bill will affect a relatively small amount of money in Rhode Island. It will require the sale, and reinvestment elsewhere, of about $2 million worth of a total $8 billion in state pension investments. Once those investments are sold, the state will periodically evaluate its portfolio to make sure more state holdings have not been added to the list of offending companies and that companies in which the state invests have not entered the list anew.

Scott Warren, a Brown University student who heads the campus Darfur Action Network, said the divestment movement among states is heartening, but “this isn’t the end.”

When Congress declared the Darfur atrocities genocide in 2004, Warren said he was hopeful that would bring the genocide to an end. “Three years later,” he said, “little has changed. Women are still being raped. Children are still starving.”

egudrais@projo.com