(Adds data and historical context)
SAO PAULO, Oct 1 (Reuters) - Brazil posted a trade deficit of $939 million in September, its first monthly deficit after six straight positive results this year, government data showed on Wednesday.
The median forecast of 12 analysts surveyed by Reuters was for a deficit of $650 million in September. The country posted a surplus of $1.17 billion in August.
So far this year the country has accumulated a trade deficit of $690 million, smaller than the $1.760 billion gap registered over the same period last year.
A drop in prices for key commodity exports like iron ore and soy has dragged down the value of exports in a country where hefty trade surpluses used to be the norm. On the other hand, imports of everything from clothes to electronics remain strong.
The South American country posted a trade surplus of $2.4 billion in 2013, its smallest surplus in more than a decade. As recently as 2011, Brazil posted a surplus of $29.8 billion, or the equivalent of 1.20 percent of gross domestic product.
Opening up Brazil to more foreign trade would be a "disaster for Brazilian industry," Trade Minister Mauro Borges said in a newspaper interview on Saturday. The comments may offer a preview of Brazilian trade policy for the next four years should President Dilma Rousseff win re-election this month. (Reporting by Luciana Otoni; Writing by Alonso Soto; Editing by Chizu Nomiyama)