* Oil, natgas Aug output 2.46 mln boepd
* August oil, gas output fell 0.5 pct vs July
* Crude output 2.01 mln bpd, lowest since October 2010
RIO DE JANEIRO, Oct 3 (Reuters) - Brazil's oil and natural gas output fell for the second straight month in August, pushing crude output to a 22-month low, after state-led Petrobras closed platforms for repairs, the oil and energy industry regulator said on Wednesday
Brazil produced an average 2.46 million barrels of oil and natural gas equivalent (boepd) in the month, down 0.5 percent from 2.47 million barrels in July, the regulator, known as ANP, said in a statement.
Crude oil output fell to an average 2.01 million barrels per day in August, its lowest level since Oct. 22. Output in South America's biggest country also fell 0.5 percent on an annual basis.
National oil output is falling despite growing spending by Petrobras, the country's dominant producer. Scheduled maintenance in the giant Roncador and Marlim Leste fields in the Campos Basin accounted for much of the decline.
Petrobras output has been declining even after it committed to spend $237 billion over five years to help the company meet its goal of more than doubling output to about 5.7 million barrels a day in 2020.
Petrobras remained the largest producer in the country with an average 2.24 million boepd in August from fields it operates or in which it has financial stake. That is 91 percent of Brazilian average output in the period.
Statoil was No. 2 with 37,737 boepd and Royal Dutch Shell was No. 3 with 36,529 boepd.
The order of the top three was unchanged from July.
Petrobras preferred shares, the company's most-traded class of stock, fell 1.8 percent to 22.30 reais, its first decline in three days.