Utilize the input text as a context reference, choose the right relationship between 888 Holdings and Gibraltar 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.

Gibraltar based gaming company 888 Holdings Plc which is owned by brothers Avi and Aaron Shaked has sent a revised proposal to the board of bwin.party.

Answer: headquarters_location