Noble, who joined the firm in 1992 and leads the global finance practice alongside Frankfurt partner Dirk Schmalenbach, will step down from the management role as soon as a successor is found and will leave the firm in October.
He said: "It's an enormous shock to be going. Lawyers are funny animals, they are very conservative and cling to these places so it has taken a huge amount of will power to do this, but I'm excited."
Noble, who acts for clients such as Babcock & Brown and Macquarie, said he will consider his options over the coming months with the expectation that he will go into some kind of management role.
"I've always had a yearning to do something else completely different before I really retire," he said. "I was 48 in January and I thought if I'm going to do that I really need to do it now. I have tried very hard to resist looking too hard because I'm in a terribly sensitive position here and it would be wrong to go running around the market looking for another job."
Stressing that he will not join another law firm, Noble said it is likely he will look for a position somewhere in the telecoms or infrastructure sectors.
"I've always enjoyed working with lots of people in different aspects of infrastructure," he said. "I'm also very interested in the world and a lot of what I've done here has focused on how the business interacts with the global economy. I'd like to continue developing the skills I have acquired on the business and management side."
During his time at Freshfields Noble has served as Asia managing partner. He is also co-head of the firm's financial institutions group.