By Huw Jones

LONDON, Sept 12 (Reuters) – The global “Basel III” deal on bank capital standards was reached at lightning speed by usually glacial regulators — substantive negotiations took about a year, compared to a decade for the current Basel II rules.

But implementing the new standards consistently over the lengthy phase-in period will be a headache for national regulators, and determine whether Basel III succeeds better than its predecessor in reducing bank sector risk.

* The Basel III rules are much tougher than Basel II, which failed to ensure banks held enough capital to withstand the worst financial crisis since the Great Depression.

* Although Basel III more than triples the amount of top-quality capital that banks will have to hold in reserve, there are several potential pitfalls in timing and content that could undermine the reform’s effectiveness.

* The key aspects of the completed package will not all be phased in until the start of 2019, presenting a challenge for supervisors and their political masters to maintain momentum in their supervision of the sector. Lobbying by banks or an eventual return to boom times could blunt the will to enforce Basel III, as memories of the global credit crisis fade.