Brazilian stocks are up modestly fternoon following the announcement that two large banks would merge, while Argentina's leading index has climbed 5.5 percent, the Associated Press reported.
Brazil's Ibovespa index was up 2.4 percent to 38,168.
Argentina's Merval index, meanwhile, picked up 55.7 points to 1,066 in afternoon trading. Mexico's IPC was down a slight 0.2 percent at midday to 20,414.
Chile's IPSA index rose 2.6 percent to 2,555. Colombia's markets were closed for a national holiday.
Monday's gains for stocks came after Banco Itau SA and Unibanco Holdings SA announced they will merge to create South America's largest private-sector banking group.
Mexico's peso strengthened slightly to 12.8 to the U.S. dollar, up from 12.9.