Papua New Guinea-focused oil and gas explorer Rift Oil has agreed terms of a takeover bid from Talisman Energy worth £108m, or 13p a share in cash.Talisman says it's received irrevocable undertakings to vote in favour of the deal in respect of 269m Rift shares, or 32% of the company.Rift, whose shares have leapt from about 3p to 10p inside six months, has now scrapped a possible farm out with a major multi-national oil company, announced last month, to help it prove additional reserves at its PPL235 licence in Papua New Guinea."Talisman believes this offer represents the full and fair value of the assets and provides Rift shareholders the certainty of cash," said Paul Blakeley, Talisman's executive vice president, international operations (East). "The acquisition will provide a low-cost opportunity to aggregate gas in Southeast Asia, one of the growth areas of our portfolio." Rift's non-executive chairman, Ian Gowrie-Smith, believes the price "suitably rewards shareholders". "It is time for those with more significant resources to take over the challenge of development and commercialization," he says.