HOUSTON--(BUSINESS WIRE)--The Angolan National Concessionaire Sociedade Nacional de Combustíveis de Angola – Empresa Pública (“Sonangol”) and Cobalt International Energy, Inc. (“Cobalt”) (NYSE:CIE) today announced the signing of a Sale and Purchase Agreement for Sonangol to acquire all of Cobalt’s 40% participating interest in Blocks 21/09 and 20/11 offshore Angola (the “Blocks”) for $1.75 billion with an effective date of January 1, 2015. This transaction is subject to customary Angolan govern