They also faced a final few hours of behind-the-scenes haggling to see whether all eight could express a joint position on ending the 2-year-old civil war in Syria. Russia's Vladimir Putin, who backs the government of Bashar Assad against rebel forces, refused to shift his stance during Monday night's working dinner on the issue. The other seven leaders, including U.S. President Barack Obama, have shown varying degrees of support for the rebels. As well as host Britain, the G-8 includes the United States, Japan, France, Germany, Italy, Canada and Russia.
British Prime Minister David Cameron is seeking a joint commitment by nations to stop paying ransoms to kidnappers in hopes of deterring the practice following January's bloody capture by al-Qaeda-linked militants of an Algerian gas facility. Ten Japanese, five Britons, three Americans and a French national were among the 40 civilians killed as Algerian forces retook the facility.
Hostage-taking of foreign workers for cash payments is on the rise across much of West Africa, particularly Nigeria with its own oil industry dominated by Western companies and foreign managers.
"I want us to discuss how we crack down on terrorist ransoms because this would suffocate one of the main sources of funding for these terrorist organizations, and of course would reduce the incentive to take our citizens hostage," Cameron said ahead of Tuesday's discussions.
Cameron has also invited the leaders of Libya and the African Union to join the talks table Tuesday.
The G-8 leaders also are expected to agree on new measures to restrict the ability of multinational corporations to avoid paying taxes in their home countries by using shell companies and other legal accounting tricks to shelter cash in principalities and islands, many of them British, that charge little or no tax.
Britain's treasury chief, George Osborne, is taking part to help explain Britain's agreement unveiled last week with its far-flung crown dependencies and overseas territories — including the Channel Islands, Gibraltar and Anguilla — to start sharing more information on which foreign companies bank their profits there.
"You're going to see concrete achievements today on changing the international rules on taxation, so individuals can't hide their money offshore and companies don't shift their profits away from where the profit is made," Osborne said.
"Of course Britain's got to put its own house in order," he added, referring to companies' practice of funneling money between the British offshore territories and the City of London, the world's second-largest financial market.
The summit is concluding with rapid-fire press conferences by each departing leader. Obama continues his European trip Tuesday night in Germany.
Associated Press writer Cassandra Vinograd in Enniskillen contributed to this report.Suggest a correction