(Adds new tightening of curb on dollars paras 5-7)
By Walter Bianchi
BUENOS AIRES, Nov 16 (Reuters) - Argentina's central bank chief on Monday opened the door to quitting early if conservative challenger Mauricio Macri wins the presidential election race, days after vowing he would see out his mandate until its 2019 end.
Monetary policymaker Alejandro Vanoli, who is seen as a trusted ally of the country's outgoing leftist president, Cristina Fernandez, said he was at odds with Macri's plan to unwind capital controls if that meant a sharp peso devaluation.
"I will evaluate my position if Macri wins," Vanoli told local TV channel America 24. "If the path chosen is ... to liberalize everything, or devalue by 50 percent then clearly I will not be in agreement and clearly I will not be an obstacle to that."
Center-right Macri has said he would expect Vanoli to resign if he wins the Nov. 22 run-off vote against the ruling party candidate Daniel Scioli.
The bank's independence has waned during Fernandez's eight-years in power. Under Vanoli's watch, the central bank has not resisted the leftist government's expansive fiscal policies amid high inflation.
The bank defends the web of controls designed to shore up Argentina's dwindling foreign currency reserves, now at a nine-year low.
On Monday, the central bank cut the daily amount of dollars companies can transfer abroad without the regulator's authorization for the second time in three weeks, five currency market traders said.
They said the central bank had called commercial banks with a verbal directive to slash the daily volume allowed per firm to $50,000 from $75,000. A central bank spokesman declined to comment.
Macri is campaigning on a platform to lift protectionist controls on the peso currency and imports from his first day in office in order to open up Latin America's No. 3 economy and win new investments.
His rival Scioli says monetary reforms need to be gradual. Scioli and Vanoli both warn the abrupt removal of the controls would send the peso weaker and push double-digit inflation higher still.
Vanoli expressed hopes for policy talks but said he would not "cling on to his title" if he opposed the monetary policy direction of the next president.
A state prosecutor last week accused Vanoli of selling U.S. dollar reserves at a cheaper rate than set by the international foreign exchange futures market.
The central bank chief denies any wrongdoing and a judge is yet to decide if there is a case to answer. (Writing by Richard Lough; Editing by Andrea Ricci and Andrew Hay)