"The flows have been resumed after a month-long halt," Tamam Bayatly, a spokeswoman for BP-Azerbaijan, said.

Last month, BP said the closure would not affect production and exports from its Azeri-Chirag-Guneshli (ACG) project.

The roughly 74,000 barrels per day the pipeline normally pumps from the Chirag field were diverted to the Baku-Tbilisi-Ceyhan pipeline during the maintenance work.