The major racing broadcaster has joined wagering operators and big names in racing by signing up for three years to the $5 million Thoroughbred race.

Racing and Wagering Western Australia Chief Executive Officer Ian Edwards said the new chapter of the TABtouch Western Trilogy had proven to be a best seller.

"The future of Western Australia's richest racing weekend is secure, with almost all the 32 original slot holders renewing their commitment for the long term and new challengers quick to seize the rare chance of joining the series," Ian said.

"Sky Racing is a leader in racing entertainment and their involvement raises The Western Trilogy to a new level.

"The broadcasting energy of Sky Racing is a welcome addition to the race series and will generate even stronger interest in the three races.

"The series was oversubscribed, with four new contenders taking slots in The Sandgroper, Sky snapping up the one that that became available in The Quokka and none were available for The Nullarbor."

For The Sandgroper race, Greyhounds HQ and MintBet each took a slot, a shuffle saw Total Container Solutions join forces with Team Britton and harness slotholders Aaron Bain Racing & Summit Bloodstock extended their involvement by also picking up a greyhound slot.

The prize pool across the three races of The Western Trilogy rises to a total of nearly $7 million in 2024.

"The Western Trilogy generated $6 million of economic value for WA this year and we look forward to making it bigger and better in 2024," Ian said.

"Our unique autumn racing carnival not only highlights the best of WA but brings the best and brightest stars of the racing world to WA."