What is the relationship between Eni and Petroleum in the context of the input sentence. Choose an answer from: product/material produced; manufacturer; distributed by; industry; position held; original broadcaster; owned by; founded by; distribution format; headquarters location; stock exchange; currency; parent organization; chief executive officer; director/manager; owner of; operator; member of; employer; chairperson; platform; subsidiary; legal form; publisher; developer; brand; business division; location of formation; creator.

The exploration and commercialization of the gas will be carried out by two private investors, Eni of Italy and Vitol Group of the Netherlands in close partnership with Ghana National Petroleum Corporation (GNPC).

Answer: product_or_material_produced