Sterling has fallen to the lowest level in more than three decades against the dollar in the aftermath of Britain's vote to leave the European Union.

Premier Oil, which is mainly spending pounds on bringing the Catcher oil field in the North Sea on stream next year, said it had saved around $100 million on that project alone thanks to the exchange rate effect.

"We will be the beneficiary of Brexit, dare I mention it," Premier Oil Chief Executive Tony Durrant told Reuters.

He said the weak currency also had a positive effect on some of its debt held in sterling.

Premier Oil said if the exchange rate remains at current levels, the company would benefit from further savings on its budget as it has forward hedged some $110 million of spending at the low exchange rate.

"Production, operating costs and capital savings could all exceed expectations this year, putting some upward pressure on our valuation," said David Round, analyst at BMO Capital Markets, who holds a 'market perform' rating on Premier Oil's stock.

Its shares were up 5.8 percent at 0723 GMT, outperforming the oil and gas company index <.SXEP> which was up 0.6 percent.

The oil company, whose operations stretch from the Falkland Islands to Indonesia, also said full-year production levels could exceed guidance thanks to strong output from some of its existing and new fields in the North Sea.

It said 2016 production could be at the top end or exceed its production forecast of 65,000-70,000 barrels of oil per day (bpd).

Premier Oil is still discussing lending terms with around 25 banks, focusing on which investments the company will want to make in future to continue to grow.

The oil producer could see some cash from the sale of its Pakistan business as it said it has agreed final terms with an exclusive bidder.

Durrant declined to give the bidder's name, saying it was confidential while it was finalising funding arrangements for the acquisition.

(Editing by Louise Heavens and Jason Neely)

By Karolin Schaps