Corn futures prices at the Brazilian Stock Exchange and the Chicago Stock Exchange opened Thursday with positive trends at 10:07 am and 10:05 am Brasília time, respectively. The main quotations for the March/23 maturity fluctuated between R$ 86.35 and R$ 87.58 in Brazil, and between US$ 5.84 and US$ 6.47 in Chicago. The increase in prices was driven by bargains and uncertainties over the potential renewal of the Black Sea grain export deal, following Russia's criticism of the West for allegedly undermining the deal.