(Adds legislator comment, U.S. rate cut)

SANTIAGO, March 18 (Reuters) - Chile central bank president Jose De Gregorio said on Tuesday the institution would avoid hasty action to combat the rapid appreciation of the peso against the dollar, but did not discard future intervention.

"Not acting is in itself a monetary policy decision that is justified under present conditions and which can change as local and global economic conditions evolve," De Gregorio told Chile's Lower House, or Chamber of Deputies.

Chile's peso is close to an 11-year high against the dollar, buoyed by extended, soaring copper prices and a widening differential between interest rates in Chile and the United States.

"We cannot discard an intervention in the exchange rate in the event that there is a disalignment that threatens the stability of the economy, in the event where we feel an intervention would be effective," De Gregorio told legislators demanding relief for Chileans suffering from the strong peso.

With the currency one of the fastest rising against the dollar this year, legislators demanded action on Tuesday from the central bank chief and warned that no action could be harmful.

"Where is the pilot here," one legislator said ahead of De Gregorio's speech to federal deputies. "We have a serious problem here ... We need a flight plan."

The peso has gained more than 14 percent against the dollar this year, among the strongest rises of any Latin American currency this year against the greenback.

The currency CHILJ<CLP=CL> strengthened 0.60 percent on Tuesday to close at 431.20/431.50 per dollar, compared with the prior session's close at 433.80/434.10.