UPDATE 1-Brazil Vale to buy oil tech firm for 15 mln reais

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SAO PAULO, Nov 28 (Reuters) - Brazilian mining giant Vale (VALE5.SA)RIO.N said on Friday it agreed to buy Petroleum Geoscience Technology Ltda (PGT), an oil and gas exploration and production company, for 15 million reais ($6.44 million).

Vale, the world's biggest miner and exporter of iron ore, is investing in natural gas to power its domestic and foreign operations.

"We are acquiring more knowledge in natural gas and oil exploration. The objective is to increase Vale's options for energy generation," executive director of non-ferrous metals and energy Tito Martins said in a statement.

Vale said it would pay the purchase price in instalments until 2013 and would rename the five-year-old firm Vale Natural Gas Exploration and Production.

The company said since last year it had been joining consortiums exploring for gas in Brazil's offshore basins where large, deep-lying resources have recently been found.

It said it held a minority stake of between 10 and 50 percent in 15 exploration blocs, meaning it would not operate them.

Vale is also a stakeholder in eight hydro-electric power plants with a total output of 2,500 megawatts.

($1=2.33 reais)

(Reporting by Peter Murphy; Editing by David Gregorio)