* Jan output down from year ago and from December
* Norway's Statoil No.2 producer in Brazil for 4th straight month
SAO PAULO, March 7 (Reuters) - Brazil's output of oil and natural gas fell for the 10th straight month in January, with maintenance of offshore oil platforms run by Petrobras limiting production in the first month of 2013, the country's oil regulator said on Thursday.
Output fell 5.5 percent to an average 2.584 million barrels of crude and natural gas equivalent per day (boepd), from 2.678 million boepd in January 2012, the ANP regulator said.
Production also fell 2 percent from December, when output was 2.584 million boepd.
Norway's Statoil ASA was Brazil's No.2 producer for the fourth straight month after surpassing Royal Dutch Shell Plc in October.
Brazil's state-controlled Petrobras is the country's largest producer, with average daily output of 2.3 million boepd in January. That accounted for 92.7 percent of all oil and 98.4 percent of all natural gas produced in Brazil.
Brazilian oil production has suffered in recent months due to declining output from mature fields owned by Petrobras and the shutting of ageing oil platforms for maintenance.
Petrobras said in a Feb. 28 statement the closure of platform SS-11 in the Bauna Field was the principal cause of its drop in production in January.
Petrobras' output is falling despite the company's $237 billion five-year expansion plan, the world's largest corporate spending program.
Brazil's natural gas output was 75.9 million cubic meters (2.68 billion cubic feet) per day in January. That was 6.75 percent more than the same month a year earlier but 0.39 percent less than in December.