"We've been in discussions with the ATC since the autumn carnival and we're disappointed that the ATC was not willing to offer Myer a long-term deal after what has been a strong partnership for seven years," a Myer spokesperson said.

ATC chief Tony Partridge said the organisation was hoping to expand local retail activity around the racing calendar, not just appear to be "simply granting sponsorship rights and category exclusivity to one partner".

"The competitive nature of the retail fashion sector and shift to online sales means there are now many retailers that benefit from Sydney racing carnivals and, of course, more retailers that can spread the word about dressing for the races," he said.

"We believe the opportunity to form marketing partnerships with many retailers and have those same retailers offer benefits to our customers is now greater than the commercial benefit of having one department store sponsor," Mr Partridge said.

In 2013, Myer re-signed a three-year deal with the ATC granting the retailer exclusive fashion rights to Rosehill Gardens and Royal Randwick.

The local Fashions on the Field competition became a highlight for many race goers, with the winner then going on to compete in the national final in Melbourne during spring racing carnival, where the prize pool is now worth more than $70,000.

Myer confirmed it would still host a NSW final in Sydney, however Mr Partridge, in a move that may irk racing traditionalists, said the ATC would explore "social media-based fashion competitions" that would not require competitors to dedicate an entire day at the races to the competition.

"We might still ask finalists to parade before the crowd but it won't take them all day and they will be chosen from a much bigger pool of entrants," he said. "We think reducing the time commitment to enter will really open the fashion competition up to many more racegoers and the entries will be more creative which we can't wait to see."

The ATC will launch the Sydney spring carnival on Tuesday at a lunch at Royal Randwick where the new carnival ambassadors will be introduced ahead of the Golden Rose Day at Rosehill Gardens next weekend.

Mr Partridge said he was now focused on meeting with interested retailers about sponsorship, one of which may be Myer nemesis David Jones. The luxury retailer announced earlier this month it would relocate its headquarters to Melbourne – racing's heartland – in the coming years.

At the time, when pressed about making further inroads into the racing world, a spokesperson said no concrete plans had been made but the retailer "is committed to the Caulfield Cup".

David Jones is a major sponsor of the meet where it regularly hosts about 250 A-list guests.