Chennai-based offshore drilling services provider Aban Offshore Ltd said it will acquire a 100 per cent interest in two oil and gas blocks in the UK North Sea but will subsequently sell half the stake. The Chennai-based company said in a stock-exchange disclosure a step-down subsidiary has signed a conditional agreement to buy the 100 per cent interest for a non-cash consideration of $75 million (Rs 556 crore). The consideration shall be set off against amounts due from certain customers for the drilling services provided by the company, it said. Subsequently, Aban Offshore will sell a 50 per cent interest in these two blocks for $37.5 million in cash to an unrelated party. The buyer will operate the blocks, it said. Both the transactions are subject to customary closing conditions, including the consent of the UK Oil and Gas Authority. Aban Offshore provides offshore drilling and production services to oil and gas companies exploration and production companies in domestic and international markets. It is also into wind energy production, but the segment contributes less than 10 per cent of the overall revenue.