* Sechin suggests 1 million bpd cut by major producers
* Rosneft CEO doesn't say if Moscow would contribute to plan
* Says oil price drop driven by OPEC decision
* U.S. shale production to peak in 2020, Sechin says (Adds details, quotes)
By Dmitry Zhdannikov and Ron Bousso
LONDON, Feb 10 (Reuters) - The head of Russian state-run oil company Rosneft on Wednesday floated the idea of a coordinated output cut by major oil-producing countries to prop up sagging prices but fell short of saying whether Moscow would contribute to such a plan.
Rosneft Chief Executive Igor Sechin, in a speech at the IP Week conference in London, attributed oversupply in the market to overproduction by members of the Organization of the Petroleum Exporting Countries.
He suggested major oil producers each cut production by 1 million barrels per day (bpd).
Oil prices have slumped more than 70 percent to near $30 a barrel over the past 18 months as supply exceeded demand by up to 2 million bpd after OPEC, seeking to drive higher-cost producers out of the market, decided not to cut production.
Struggling oil-producing countries have urged OPEC leader Saudi Arabia in recent weeks to call a special meeting to discuss output cuts. Riyadh has indicated it would be willing to consider a cut only if all major producers agreed to one.
Sechin nevertheless said U.S. shale production, a key driver behind the global glut, would decline in the long term.
"Shale oil production has its limitations in scope and time ... U.S. shale oil production will reach its peak in 2020," he said.
Sechin, a close ally of Russian President Vladimir Putin, said however that onshore U.S. producers had proven more resilient to the oil price downturn.
"Shale oil markets reacted very quickly to the price shock as productivity rose dramatically, costs of production dropped and fracking became more efficient," Sechin said.
Sechin said he expected Iran to ramp up oil production to between 5 million and 6 million bpd by 2025. (Reporting by Dmitry Zhdannikov and Ron Bousso; Editing by Dale Hudson and Louise Heavens)