Chile's leading air carrier LAN Airlines led the blue chips in gains and volume as its stock jumped 2.03 percent to 3,480.50 pesos a share. Analysts say the recent easing of fuel prices has given the expanding company a boost.
Almost all of Chile's biggest publicly traded companies are due to report third quarter earnings on Thursday and Friday.
Chile's largest department store and retail banking chain Falabella was the other big gainer as its stock rose 1.9 percent to 1,400 pesos a share. Copper manufacturer Madeco, which was one of the few companies to publish its quarterly report on Wednesday, rose 0.25 percent to 48.25 pesos a share in listless trade.