18 May, 11:09
IRFU Chief Executive Philip Browne has issued a statement following confirmation of Ronan O'Gara's decision to retire from playing professional rugby.
He began his career with Sale and Leeds and has spent the last five seasons at the London club, although he did enjoy an impressive loan spell with Munster during the 2006/07 season.
He has representative honours at Under-21 level, and was part of Engand's Grand Slam-winning squad in the 2004 U-21 Six Nations Championship.
Commenting on his new move, Kyriacou said: "I've heard a lot of good things about Matt Williams. He's got a good young squad at Ulster that are looking to go places and it will be exciting to be a part of that.
"I thoroughly enjoyed the short period I had in the Magners League with Munster. It's a very competitive league with rugby that's fast and tough and there are no weak teams in there."
Kyriacou will find himself competing with Ireland hooker Rory Best for a place in the Ulster starting line-up, as well as the experienced Nigel Brady.
Indeed, he played against Ulster captain Best when both were playing for their national Under-21 sides.
"Obviously I'll have to work hard for a starting place in the squad with stiff competition from Rory and Nigel, but I'm really looking forward to a fresh challenge and intend to compete for a place," he added.