Scottish oil and gas giant Cairn Energy is to make an agreed takeover of North Sea oil producer Nautical Petroleum.Cairn is offering 450p per share in a deal which values Nautical at around £414m. The terms represent a 51.1% premium to the closing price of Nautical on the trading day prior to the announcement of the bid.Cairn said the acquisition would expand its existing portfolio in North-West Europe and will further its strategy of balancing its exploration portfolio with appraisal and development assets. Nautical's oil and gas assets consist of development assets in the United Kingdom North Sea (including interests in the Catcher, Kraken and Mariner fields) and exploration assets in the United Kingdom, Ireland and France.Shareholders representing around 27.25% of the issued share capital of Nautical have already signed up to accept the terms, which have the approval of the Nautical directors. JH