Co-opetition is a business strategy which combines co-operation and competition, based on the concept that business competitors can benefit when they work together.

The co-opetition business model is based on games theory, a scientific approach to understanding various strategies and outcomes through specifically designed games.

Businesses succeed by combining cooperative strategies with competitive strategies. Other businesses do not have to fail for others to succeed. They cooperate to enlarge the pie and compete to divide it up. Traditional business philosophy translates to games theory’s zero-sum game in which the winner takes all, and the loser is left empty-handed; whereas the co-opetition approach leads to a plus-sum game, in which the sum of what is gained by all players is greater than the combined sum of what each of the players started with.

See this ‘Ideas in Action’ article about two art galleries in Vietnam that co-operated with competitors for mutual advantage:
Co-opetition – friendly competition