The document was signed on the sidelines of the 23rd International Oil, Gas, Refining and Petrochemical Exhibition in Tehran.
Jafar Rabiei, the managing-director of Persian Gulf Holding, said after the signing ceremony that the major world companies have to know that Iran's situation is not the same as pre-sanctions era.
'From now on the relations with Siemens are not confined to buying commodities. Rather the two companies will have long-term cooperation on repairing, maintenance and upgrading the quality of products.'
'Today Siemens has reached the conclusion that Persian Gulf Holding cannot be ignored and the two companies can focus on joint cooperation,' Rabiei said.
The 23rd International Oil, Gas, Refining and Petrochemical Exhibition opened in Tehran on Sunday with participation of 1,053 domestic companies and 600 foreign ones from 37 countries and will continue until May 9.