By Huw Jones
LONDON (Reuters) - Banks face curbs on their ability to downplay how much capital they should hold, as regulators bid to restore investor confidence in the sector, a top global banking watchdog has said.
Stefan Ingves, chairman of the Basel Committee of supervisors from nearly 30 countries, said there will be "floors" on bank capital, one of the most definitive statements so far on major changes to come.
A floor forces a bank to hold a certain amount of capital regardless of what its risk modelling says it should hold.
In a speech published on Thursday, Ingves told banking supervisors meeting in China that differences in how banks use models to calculate capital buffers were too great.
"The steps the committee has taken, and plans to take, to address excessive variation in risk-weighted assets include the introduction of capital floors ... and greater restrictions on the scope of banks' internal risk estimates," Ingves said.
The committee will spell out its measures to leaders of the Group of 20 governments (G20) in November, Ingves added.
Basel has faced pressure from U.S. and British regulators to simplify capital rules.
The committee was lukewarm initially but Ingves signalled the ground was shifting, saying internal models at banks cannot capture all risks adequately, meaning blunter tools will be needed in some cases.
"There needs to be more restrictions on modelling assumptions and techniques and an acceptance that not all risks can be modelled," said Ingves, who also heads Sweden's central bank.
Finding a new balance between complexity and simplicity was "becoming ingrained in the mindset of those responsible for policy development and implementation," Ingves said.
Some regulators have lost patience with Basel and are introducing rules nationally that are tougher than Basel III.
The United States has introduced a much tougher leverage ratio on lenders and Britain may force banks which use internal risk models to publish capital calculations using the so-called standardised model as well.
Ingves said the Basel Committee has approved a final version of its net stable funding ratio which limits how much a bank can use illiquid assets to fund short-term borrowings. The final standard will be released in coming weeks and take effect from the start of 2018.
(Editing by David Holmes)