Utilize the input text as a context reference, choose the right relationship between Sergio Marchionne and Fiat from the options. Options: 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.

FRANKFURT (Reuters) - Fiat plans to keep all German Opel plants open should its takeover plans for the General Motors unit succeed but would cut staff there, Fiat Chief Executive Sergio Marchionne told a newspaper.

Answer: employer