(Adds detail and central bank estimates for November)
BRASILIA, Nov 24 (Reuters) - Brazil's current account deficit widened in October from the previous month, highlighting the rapid deterioration of the external accounts as prices of key exports drop sharply.
The country posted a current account deficit of $8.131 billion in October, the largest ever for that month, central bank data showed on Monday. That was above an expected gap of $7.5 billion, according to the median forecast of 14 analysts in a Reuters poll.
Brazil's current account deficit in September was $7.907 billion. The current account is a country's widest measurement of foreign exchange flows, including trade, services, interest payments and remittances.
In the last 12 months through October, the current account deficit was equivalent to 3.73 percent of Brazil's gross domestic product, the highest since 2001.
The widening deficit threatens to surpass the central bank estimate of a cumulative $80 billion shortfall this year. So far in 2014, Brazil has accumulated a deficit of $70.697 billion.
The central bank expects a current account deficit of $8 billion in November, its head of research, Tulio Maciel, told reporters in Brasilia.
Brazil's trade balance could turn negative this year for the first time in more than a decade as the price of iron ore and soy drop. The South American nation is one of the world's top exporters of commodities.
Foreign direct investment (FDI), however, has remained robust, but not enough to cover the current account deficit. So far this year, Brazil has attracted $51.194 billion in foreign direct investment.
In October, the country saw FDI inflows of $4.979 billion, above market expectations for $4.2 billion. (Reporting by Alonso Soto and Luciana Otoni; Editing by W Simon and Paul Simao)