The International Energy Agency approved Nigeria to join as an association country, expanding its ties with one of Africa's largest oil producers, the Paris-based organization says. "Nigeria is a major producer of oil and natural gas and is one of the continent's most dynamic renewable energy markets," the agency says. According to the IEA's latest monthly report, Nigeria's crude oil production averaged 1.47 million barrels a day in May. The IEA has 32 member countries, all of which are also part of the OECD, while its association program allows it to work more closely with selected emerging economies. Nigeria is not a member of the OECD. (giulia.petroni@wsj.com)