Grupo BTG Pactual SA (BBTG11), the Brazilian investment bank led by billionaire Andre Esteves, fell the most in seven months after the exchange said a 5.38 percent block of the company’s shares will be sold at a discount tomorrow.

Shares of BTG Pactual fell 4.3 percent to 31.50 reais at 3:21 p.m. in Sao Paulo after earlier sliding as much as 6.9 percent in the steepest intraday drop since June 8. The benchmark Bovespa index slipped 0.2 percent.

Unidentified investors will sell about 6.5 million shares tomorrow between 10:30 a.m. and 10:45 a.m., exchange operator BM&FBovespa SA (BVMF3) said today in a statement. The price will be 29.50 reais a share, 10 percent below yesterday’s closing level, the exchange said.

Sao Paulo-based BTG Pactual will broker the sale, according to the statement. The sellers are not controlling shareholders and do not know “any relevant information about the company that isn’t public,” the exchange said.

The exchange announces and holds such “special sales” to ensure all investors have a fair chance to bid on the discounted shares.

Today’s drop left BTG Pactual shares below its April 2012 initial public offering price of 31.25 reais.

To contact the reporter on this story: Denyse Godoy in Sao Paulo at dgodoy2@bloomberg.net

To contact the editor responsible for this story: David Papadopoulos at papadopoulos@bloomberg.net