The Monetary Authority has conducted foreign exchange transactions to buy $51 billion worth of Hong Kong dollars to support the local currency since April 12.

Speaking to the media today, the authority's Deputy Chief Executive Howard Lee said the move was in accordance with the Linked Exchange Rate System.

"We see that the operation of the market has been smooth and orderly and the market confidence in the ability of the Hong Kong Monetary Authority to maintain stability of the Hong Kong dollar is very strong and also, there is very strong confidence in the Linked Exchange Rate System.

"The amount and the extent of the outflow would depend very much on market sentiments and also market views on a number of issues including the path of the US dollar interest rate, the demand for Hong Kong dollar in Hong Kong and a number of other issues."

He noted the amount and the pace of the capital outflow are consistent with the authority's analysis and expectation.

The authority will remain vigilant and watch the market carefully, he added.