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Shares in 31 companies will trade three times a day to "contain volatility," the exchange said in a statement. There will be a morning session that lasts 90 minutes, a midday session that lasts one hour, and a closing session that lasts a half hour.
Companies to be included in the new regime include bank Banco Santander Rio SA, electricity distributor Edesur , Petrolera del Conosur SA - a subsidiary of Venezuela's state oil company PDVSA - and confectioner Havanna Holding SA, whose shares debuted last year.