Bank of Canada Governor Mark Carney said on Monday he would be taking on the biggest challenge going when he heads up the Bank of England next year, joining the institution as it wins a broader, bigger role.

"I'm going to where the challenges are greatest," Carney told an Ottawa news conference, adding he would not be moving if he did not feel the Canadian financial system was in top shape.

"We have a system that works very well. It's been tested under the biggest economic shock and financial shock that any of us will ever see in our lifetime, and it has passed that test."

Describing an "on-and-off" debate about his being chosen for the new job, Carney cited what he called the very positive challenge of the continuing reform of the British financial system as factoring into his final decision.

He said Britain was leading the world in these reforms, in many respects, but reforms had to be seen through, and he also wanted to help in the rebalancing of the British economy.

"Where I saw strengths here and confidence here, I weighed that against the needs and the real challenges in the UK and came to this decision," said Carney, who will keep his role as head of the global Financial Stability Board, which is tasked with making the world financial system a safer place.

Carney also referred to "the real management challenge of an institution which obviously has the longest, most storied history among central banks but is gaining a series of new powers and needs to be relaunched."

"It's very important for the global economy that the UK does well, that it succeeds in this rebalancing of their economy, that the reform of the British financial system is completed..., that the European transition comes to fruition; I will play a role there."

Carney is arguably the most ambitious Bank of Canada governor in recent memory, supremely confident in his abilities from his time as a banker at Goldman Sachs , then the Canadian finance department and the Bank of Canada.

His reputation for seeking challenges had fueled speculation he could run for the leadership of the Liberal Party of Canada.

Carney will continue to serve at the Bank of Canada through June 1 and then start at Bank of England on July 1.

(Reporting by Randall Palmer; Editing by Tim Dobbyn)