Finance Minister Ishaq Dar said on Thursday the government will launch an inquiry into why the rupee plunged 3.1 per cent a day earlier and said a new central bank governor would be appointed within two days.

Dar said there was no justification for such a sharp drop, contradicting a statement by the country's central bank, which backed Wednesday's fall in the rupee and said an exchange rate of 108.25 against the dollar would ease balance of payments pressures.

Analysts said the State Bank of Pakistan (SBP) had effectively allowed the rupee to devalue by 3.1 per cent after nearly two years of being stable at about 104-105 rupees to the dollar.

The government has long resisted calls to allow the rupee to weaken, and Wednesday's sharp drop appeared to come as a surprise.

Dar said the government will "take actions" after the inquiry report is received, but did not specify what steps might be taken.

"I don't believe that any individual has this kind of authority to make such a big decision to make an artificial adjustment, and I am calling this artificial," he added.

The minister also said a new central bank governor would be appointed either tonight or on Friday. He did not say if Riaz Riazuddin, the acting governor will be in the running for the job.