REUTERS/Benoit TessierPARIS/COPENHAGEN (Reuters) - Total is buying Maersk's oil and gas business in a $7.45 billion deal which the French energy major said would strengthen its operations in the North Sea and boost earnings and cash flow. For Danish company A.P. Moller Maersk, the sale of Maersk Oil, with reserves equivalent to around 1 billion barrels of oil, fits with a strategy of focusing on its shipping business and other activities announced last year. The world's top oil companies have been back on the takeover trail over the last year, helped by signs of a recovery in the oil market. Total expects its biggest oil deal since it acquired Elf in 2000 to generate financial synergies of more than $400 million per year, in particular by combining assets in the North Sea. Total has been betting on new rather than mature fields in the North Sea and the acquisition gives it further economies of scale by making it the second largest player in the region. The deal illustrates Total's strategy of using a strong balance sheet to acquire attractive assets from competitors having emerged from the prolonged oil downturn stronger than some of its rivals. "It was time for us to do what a real oil and gas company would do in a period such as this when prices are lower and costs are down.