Oil producer Premier Oil has increased its 2015 exploration budget by $20 million to account for higher investments in its drilling campaign in the Falkland Islands, the company said in a trading update on Thursday. The London-listed firm, whose operations stretch from the Falkland Islands to Indonesia, also said it had received an offer for its Pakistan business and was starting a process with interested parties to dispose of those assets. The company expects revenue in the first half of 2015 of $580 million, down 34 percent from a year earlier due to lower oil prices and lower production levels as the result of a disposal. Premier Oil is scheduled to report half-year results on August 20.