NEW YORK, Sept 3 (Reuters) - Halliburton Co. (NYSE:HAL - news) Chief Executive David Lesar told investors on Wednesday that Iraq holds "enormous opportunity" for energy companies, but cautioned the major Western oil majors face a long wait before they get their turn. Lesar, who recently returned from a visit to Iraq, said local oil executives there intend to first develop known resources and then to resume negotiations with foreign oil companies under way before the war. Only then will Iraq's oil industry begin pursuing projects with the big global energy producers, he said. "If you're an oil company, the...