NEW YORK, May 19 (Reuters) - A Federal Reserve Bank of New York official responsible for implementing monetary policy on Tuesday said the central bank's current rate control toolkit would still work in a system allowing banks to hold fewer reserves.

New York Fed System Open Market Account manager Roberto Perli also said the pace of future Treasury bill buying will be determined by market conditions.

"While the current implementation framework is demonstrably very effective, there is an active public debate about the quantity of reserve supply that it entails," Perli said in the text of a speech to be delivered before a conference held by the Atlanta Fed.

"The current ample reserves implementation framework is well equipped to handle a reduction in the SOMA portfolio" if there were changes in the financial system that allowed for lower levels of reserves, Perli said.

The official also said that Treasury bill buying the Fed embarked on at the close of last year to rebuild liquidity after several years of shrinking Fed holdings will be managed flexibly going forward. It has already been reduced from buying $40 billion per month to the current pace of $10 billion.

"We stand ready to adjust the pace of (Reserve Management Purchases) up or down as necessary," Perli said.