China National Petroleum Corp. and Abu Dhabi National Oil Co. could sign a preliminary agreement later in July to invest in oil and gas exploration and refinery projects, Reuters reported July 6, citing sources.

The deal is expected to be signed during a high-level Chinese state visit to the United Arab Emirates where China National Petroleum Corp. Chairman Wang Yilin will be part of the business delegation.

China National Petroleum Corp. subsidiary CNPC International Ltd. will take the lead in talks with Abu Dhabi National Oil Co., one source told Reuters.

"It will be a preliminary and broad cooperation deal that covers upstream and downstream investment," the source said.