Group One races in Sydney will be worth a minimum $500,000 next year following a significant prize money injection by the Australian Turf Club.

The ATC announced on Thursday it would be investing a total of $2.4 million into its signature autumn carnival races.

The Sydney Cup and Randwick Guineas received the biggest boost with prize money for both races increasing by $400,000, putting the total purse at $2 million and $1 million respectively.

Prize money for The Galaxy rose $300,000 to $700,000, the same value as the Ranvet Stakes which will increase by $200,000 in 2016.

The ATC said the initiative was aimed at attracting the world's best horses to Sydney.

"The autumn prize money increases allow trainers with horses of all ages and across all distance ranges to start, build and finish their campaigns all in Sydney," said ATC chief executive Darren Pearce.

"Last year we had horses from Japan, Hong Kong and Europe come to Sydney and, with Canterbury Park's quarantine centre fully operational, we are aiming to have even more international runners."

The prize money increases come a week after the ATC announced an operating profit of almost $11 million in the 2015 financial year, a $7.2 million increase on the previous year.