Mathers was an ever-present for Leeds this season until his injury

The 22-year-old, out for the rest of the season after knee surgery, is expected to be fit to start training with the new franchise in November.

Mathers will join Great Britain winger Brian Carney at the Titans.

"We've signed him as a very capable first-grader," said Titans coach John Cartright. "He will be good for us."

The Titans' squad also includes Australian internationals Scott Prince (scrum-half) and Luke Bailey (prop forward) and Penrith's stand-off Preston Campbell.

"I am hugely honoured to be given an opportunity that very few British players get and I am looking forward to getting out there and being part of making the Gold Coast Titans a success," Mathers said.

"It has been without doubt the biggest decision I have ever had to make.

"The Rhinos is a special place and it will be a big wrench to leave the club, but it may be a once-in-a-lifetime opportunity for me and my partner to sample a new lifestyle and challenge."

Mathers' team-mate Chev Walker has also turned down a new contract as he too looks at the possibility of forging a career in Australia.

The 23-year-old, who made his first-team debut at the age of 16, is now in the final season of a five-year contract agreed in 2001.

He said: "The Rhinos offer was a good one and I've no interest in playing for another Super League club.

"But I am keen to play in the NRL and for that reason I want to keep my options open."