LAGOS (Reuters) - The world's biggest cement maker, Lafarge, signed an agreement with Chinese supplier CBMI Ltd to expand its Nigerian plant and double output to 4 million tonnes a year, Lafarge's Nigerian unit said on Thursday. Lafarge said the deal signed in Paris on Monday was a demonstration of its faith in the Nigerian economy and a response to ballooning local demand for cement. Nigeria's Lafarge Cement WAPCO did not state the value of the contract or say when it would be completed by CBMI, which is part of China's Sinoma International Group. "This investment is expected to increase the company's production from the present 2 million tonnes of cement per annum to 4 million tonnes per annum," Lafarge said. The deal is part of Lafarge's programme to build 45 million tonnes of new cement capacity between 2006 and 2010, in order to meet growing construction needs in emerging markets. Two weeks ago Lafarge WAPCO shareholders gave company directors the go-ahead to raise 75 billion in new equity to build a new production line. Africa's top oil producer has seen a strong construction boom in the last six years, which has driven demand for cement to around 14 million tonnes per year from 8 million tonnes previously. | 
