Sheffield's rival professional clubs are to wear identical logos for the first time in their history following a joint shirt sponsor deal.
The one-year agreement is thought to be worth a six-figure sum to Sheffield United and Sheffield Wednesday.
Both clubs said the partnership with firms Gilders and Westfield Health was a positive move for their supporters and the city.
It is the first time a deal like this has been agreed in English football.
Sheffield United chairman Kevin McCabe said: "With this deal the city has added yet another first to the history books."
Chairman of Sheffield Wednesday Milan Mandaric said: "This is an exciting partnership for all concerned."
The two clubs came together to negotiate the deal when local firms said that they would not want to sponsor only one of the city's teams for fear of being accused of favouring one over the other.
The agreement means Gilders, a Volkswagen dealership, will appear on the front of Wednesday's shirt when they are at home and United away. Westfield Health, a health insurance firm, will appear on United's home shirts and Wednesday's away shirts.
Sheffield Wednesday supporter BigArby on Twitter said: "I think it's a great idea."
Another Sheffield United fan said: "I don't see what harm this does whatsoever, if the deal brings the most cash in then get it done."
Both clubs will be playing in League One next season. Celtic and Rangers have shared sponsors in the past.