Leopardstown are seeking a new sponsor for the race best known as the Hennessy Gold Cup after the current backer ended its 25-year association with the race.
The three-mile event was first run in 1987 as the Vincent O'Brien Irish Gold Cup, with Hennessy beginning its sponsorship of the Grade One contest in 1991.
However, Edward Dillon & Co, which distributes Hennessy in Ireland, has opted not to continue their support of the race.
Chief executive Andy O'Hara said: "In this our 250th anniversary year and following the 25th running of the Hennessy Gold Cup, we have reluctantly decided not to extend the sponsorship beyond 2015.
"We have had a wonderful long-standing relationship with Leopardstown over the years and we thank them for their dedication and commitment to this multifaceted sponsorship."
The likes of Carvills Hill, Beef or Salmon, Dorans Pride, Florida Pearl, Neptune Collonges and Sir Des Champs all feature on the roll of honour and Leopardstown's chief executive Pat Keogh believes the race provides an excellent sponsorship opportunity.
He told www.leopardstown.com: "We are extremely grateful to Hennessy for their huge contribution to Leopardstown over the past 25 years. Gold Cup Day at Leopardstown is one of the premier sporting occasions each year and is the only race day in Ireland with four Grade One races.
"This is a wonderful opportunity for a new partner to become part of a very special sporting event."