Newport Gwent Dragons Team Manager Jim McCreedy said: "We wish Michael and his family much success in his new venture. We fully understand his decision to experience rugby in a new environment, having been ever-present since the formation of regional rugby within Wales. We thank Michael for his outstanding contribution both on and off the field.
"This gives us the opportunity to invest in new talent and to further develop our young back row players who have shown their potential this season, namely Dan Lydiate, Lewis Evans and James Harris who have all experienced rugby in the European Cup."
The Dragons back row forward has signed a deal that will keep him at the North London club until 2010, following five years with the Dragons region. He commented: "I am incredibly grateful for the support I've received from the Dragons since signing at the very beginning and have enjoyed and benefitted from my time here. Moving away from Wales and the Dragons has come at an opportune time for myself and my family.
"I am excited about the prospect of developing my rugby experience further and, as a father, I think that my children are of an appropriate age to make the move. I will always keep a close eye on the Dragons while I'm away and hope to return to the region in some capacity in the future."
Newport Gwent Dragons Chief Executive Gethin Jenkins added: "The door will always be open for Michael's return."