Vale SA, the world’s largest iron-ore producer, traded at a decade-low after plunging as much as 12 percent Monday. Mobile-phone company Oi SA tumbled 8.7 percent to a record as a measure of valuation sank to about one-tenth its average. Steelmaker Metalurgica Gerdau SA led the Ibovespa’s losses, falling as much as 16 percent.

“Concern is spread all over Brazilian companies and sectors, and we don’t see an end to this downtrend because the economy is decelerating and politics are still very messy,” said Paulo Henrique Amantea, an analyst at brokerage H.H. Picchioni in Belo Horizonte, Brazil. “We’re not recommending any stock to any investors.”

Sixty-three of the Ibovespa’s 66 members fell as Brazilian equities joined a global selloff in stocks and currencies amid concern that China’s economy is slowing faster than previously expected. Brazil would be hit particularly hard by a slowdown in demand from the Asian nation, its top trading partner and the world’s second-largest economy.

Brazil’s real dropped 1.3 percent to 3.5451 per dollar as of 12:23 p.m. in New York, providing some relief to exporters that benefit when their goods become cheaper in dollar terms.

As the Ibovespa sinks this year, its best performing stocks have been companies that depend on overseas sales of products that haven’t been hit by the commodity selloff, such as paper makers Fibria Celulose SA and Suzano Papel & Celulose SA, which have each gained more than 40 percent.

As the MSCI Brazil index reached its lowest since 2005, banking stocks and companies that make consumer staples held up better than average. Banco Bradesco was little changed Monday, making it the best performer on the MSCI Brazil Financial index. Itau Unibanco Holding SA slipped 1 percent, putting its price-to-earnings ratio at the lowest since 2007.

“If someone is looking for bargains, banks, especially Itau, are a good option,” Amantea said. “Lenders have very resilient operations in the country and could suffer a little less than the rest.”