Peter Snowden says the opportunity to build and run a family stable is the main reason for his decision to walk away from the "the best job in racing".

Snowden shocked the racing industry when he announced this season would be his last after six years as the head trainer for thoroughbred giant Darley Australia.

He is set to leave the Australian arm of Sheikh Mohammed's global racing empire at the end of the Sydney autumn carnival.

And he says his decision is family inspired as he plans to start a training partnership with his son Paul.

"It's my decision to do what I've done," Snowden told Sydney radio station Sky Sports Radio.

"I'm leaving the best job in racing (but) it's a decision I'm happy with and Paul's happy with."

Paul Snowden has been his father's right-hand man at the helm of a Darley operation that has stables in Sydney and Melbourne.

He has been at the forefront of Darley's Melbourne success for the past five years with last month's Caulfield Guineas win with Long John and Guelph's Thousand Guineas victory among the triumphs.

Snowden said he was excited by the opportunity to work even closer with his son.

"I thought it was the right time (to leave)," he said. "We are both young enough to work hard to build up a team.

"We can work together for a while and then maybe a bit later I can step back and let Paul take the reins if he wants to.

"It will be an exciting challenge for us all."

Snowden has seven runners entered for Randwick on Saturday including the two favourites in the TAB Rewards Plate (1000m).

Both Stephanson and Occitan are first starters but the latter has been well-tried in early betting, backed from $5 to $2.80.

Snowden will be trying to win his third Sydney two-year-old race in as many weeks with the pair.