What is the relationship between Repsol 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.

BP, Statoil (Xetra: 675213 - news ) , Anadarko Petroleum Corp. , Repsol and Total (Swiss: FP.SW - news ) are the main foreign energy firms in Algeria.

Answer: product_or_material_produced