South Korea\'s top steelmaker POSCO said Wednesday it signed a deal with Mechel OAO of Russia to cooperate in natural resource development and industrial infrastructure building in the resource-rich country. The memorandum of agreement (MOA) calls for the joint construction of stainless steel plants with the Russian mining and metallurgical company, and the building of support facilities at the Elga coalfield in Siberia with an estimated deposit of 2.2 billion tons.