Utilize the input text as a context reference, choose the right relationship between 3i Infrastructure and Investment 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.

COPENHAGEN, July 7 (Reuters) - Investment firms 3i Infrastructure and AMP Capital have agreed to buy Danish shipping company Esvagt for 4.1 billion Danish crowns ($607 million), aiming to tap growing demand for servicing offshore wind farms.

Answer: industry