Utilize the input text as a context reference, choose the right relationship between Statnett and transmission system operator 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.

The estimated cost of the project is between 1.5 billion euros and 2 billion euros, shared jointly by Norwegian transmission system operator Statnett and National Grid.

Answer: industry