WELLINGTON, Oct 1 (Reuters) - The Reserve Bank of New Zealand...

WELLINGTON, Oct 1 (Reuters) - The Reserve Bank of New Zealand (RBNZ) said on Tuesday that its final decision on a proposal to increase the amount of capital banks must hold will be announced in December, and it is considering all suggestions made by external experts.

The central bank on Tuesday released reports by three independent experts who have given their views on the proposal, which plans to raise top banks' capital ratio to 16% to reduce risks in case of a major financial shock.

The RBNZ said it was reviewing points raised by the experts, including a range of views on the possible interest rate impact of the proposal. It was also looking at refining estimates on the cost and benefits of the proposal, and the impact on the broader financial system.

The RBNZ received more than 160 submissions on the capital requirement proposal. The submissions were made public by the regulator in July.

Top Australian banks, which are the biggest lenders in New Zealand, have said they would have to scale back or sell their businesses in the country if it pushes ahead with the plans, due to the costs involved.

In its annual report released on Monday, the RBNZ said some commentators had supported better capitalised banks as long as it did not unduly reduce the availability of credit or increase retail interest rates.

"We are also aware that there are a range of views about how capital should be defined, the level of regulatory capital, the cost of equity and the timeframe for increasing capital," the RBNZ said in the annual report.