At The Races has expressed disappointment in losing media rights to rival Racing UK to broadcast racing in Ireland from the start of 2019.
The switch was announced on Tuesday after Racecourse Media Group (RMG) and Sports Information Services (SIS), which holds the racing rights in Ireland, extended their relationship to encompass direct-to-home streaming rights from all 26 Irish racecourses.
In a separate deal RTÉ last week announced a new broadcasting deal for increased live coverage of Irish horse racing for the next three years on terrestrial television.
Under that new agreement, RTÉ will broadcast between 25 and 27 days of live Irish racing television coverage each year for the next three years, featuring the great days of all the major festivals, with live television coverage also simulcast on RTÉ Player within the Republic of Ireland.
Despite the setback for At The Races, their chief executive Matthew Imi insists he is optimistic that future plans for the channel, which has also lost broadcasting rights to cover Chelmsford City, will not suffer as a consequence.
Imi said: "Naturally we are disappointed that our relationship with Irish racing will be coming to an end and, of course, we wish the sport well with the path it has chosen to take from next year.
"The focus for us is continuing to grow and diversify our own business and the exciting plans we have for the future of ATR remain very much on track."
The new agreement with RMG, which will take effect from January 1 2019 and run until the end of 2023, was ratified by the Association of Irish Racecourses (AIR), who together with Horse Racing Ireland (HRI) have a deal regarding broadcasting rights with SIS.
HRI chief executive Brian Kavanagh said: "This deal is a very positive one and is in the best commercial interests of Irish racing.
"It secures income streams for media rights for the next six years and aligns all of our rights across all platforms with the same strong partners."
RMG chief executive Richard FitzGerald said: "This agreement means for the first time, viewers can enjoy the major storylines of both jumps and Flat seasons in Ireland and Great Britain on one HD channel."