Stories by Iran appeared Wednesday to back a plan laid out by four influential oil producers to cap their crude output if others do the same, though it offered no indication that it has any plans to follow suit itself.

The agreement reached in Doha the day before by Qatar, Saudi Arabia, Russia, and Venezuela is aimed at stabilising global oil prices, which recently plunged to less than US$30 a barrel, a 13-year low. But Iran is keen to ramp up exports to regain...