DUSHANBE, July 14, Asia-Plus - Russian energy giant Gazprom [RTS: GAZP] and Iran''s Ministry of Petroleum will sign on Sunday a memorandum of cooperation in the oil and gas sphere, an Iranian deputy oil minister said.

"Interaction between Iran and Russia in all spheres and especially in the energy sphere is very wide. We expect to further broaden this cooperation in the future," Hossein Noghrehkar Shirazi said.

Shirazi said a series of discussions would precede the signing of the cooperation memorandum.

Iran ranks fourth in terms of crude reserves after Saudi Arabia , Iraq and Kuwait , as well as fourth in terms of oil production after Saudi Arabia , the United States and Russia . Iran ''s proven gas reserves total more than 28 trillion cubic meters.