* October oil, gas output fell 2.06 pct vs Oct. 2011
* Petrobras accounted for 92 pct of Brazil output
* Statoil production rose 32 pct from year earlier
RIO DE JANEIRO, Dec. 5 (Reuters) - Brazil's output of oil and natural gas fell in October for a seventh straight month, as maintenance of Petrobras' offshore oil platforms limited output from the country's most productive area, Brazil's oil regulator, the ANP, said Wednesday.
Output fell 2.06 percent to 2.47 million barrels of crude and natural gas equivalent per day (boepd) from 2.52 million boepd in October 2011.
Production, though, was 4 percent greater than in September, when output reached its lowest level in nearly three years.
Norway's Statoil ASA overtook Royal Dutch Shell Plc. to regain its spot as Brazil's No. 2 producer after Brazil's state-controlled Petrobras.
Brazilian oil output has suffered in recent months because of declining output from mature fields owned by Petrobras and the shutting of ageing oil platforms for maintenance, primarily in the Campos Basin near Rio de Janeiro. The Campos Basin is the source of about 80 percent of Brazil's output.
Petrobras' output is falling despite the company's $237 billion five-year expansion plan, the world's largest corporate spending program.
Rio de Janeiro-based Petrobras, with average daily output of 2.26 million boepd day, accounted for 92 percent of all oil and natural gas produced in Brazil in October.
No. 2 Statoil saw output jump by nearly a third to 40,972 boepd from a year earlier. October Statoil output in Brazil was 16 percent greater than in September.
OGX Petroleo e Gas SA, the No. 2 Brazilian oil producer, moved up one spot in the over-all ranking to seventh from eighth in September even as output slipped 0.5 percent to 10,328 boepd.
OGX began producing oil in January.
Natural gas output reached a record 73 million cubic meters (2.58 billion cubic feet) a day in October, 10 percent more than a year earlier and 1.81 percent more than in September.