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.

Several months ago, Fiat Chrysler CEO Sergio Marchionne sent Barra an email saying he wanted the two companies to merge, a notion Barra has consistently said she and the company's board of directors are not interested in.

Answer: employer