Ireland's player of the year for his starring role in the 2014 Six Nations success, Trimble said he feels "nothing but gratitude" for "some of the most fulfilling days of my life" representing Ulster and Ireland.

The 33-year-old racked up 77 tries in 229 appearances for Ulster and 17 tries in 70 Ireland caps.

He made his announcement with an open letter to supporters:

"I know that I’ve been incredibly fortunate to have realised not one of my dreams, but two of them; to play for Ulster and to play for Ireland," wrote Trimble.

"These have been some of the most fulfilling days of my life and I feel nothing but gratitude for them.

"But there’s no way of stopping time – and I see that each day in the lives of my two young children, who are now close to beating me over five metres.

"So I wanted to let you know that this will be my last season playing professional rugby.

"I want to thank the club for allowing me the time and space to think things through before making what is probably the toughest decision that any professional sportsman will make.

"Most of all, I want to thank you – the loyal and dedicated supporters of this special club.

"I know that nothing will come close to the experience of taking the field and hearing you raise your voices in support of the team.

"You stood up for me; I only hope that I stood up for you.

"With deepest thanks,

"Andrew Trimble."

Ulster missed out on the PRO14 knockout stage this year, but may face a Champions Cup play-off later this month.

Bryn Cunningham, Ulster's Operations Director, said: "I was still playing here when Andrew first joined the squad and it's been fantastic to follow his journey to becoming the highest-capped Ulster player of all time - a remarkable achievement!

"Andrew has been a class act both on and off the pitch. He has been a great ambassador for Ulster Rugby, having done much to promote our work in the community and to inspire future generations of rugby players from across the nine counties."