EMERGING MARKETS-Argentina stocks, peso firm amid IMF talks optimism

(Updates with details from Brazil, Mexico, NAFTA) BUENOS AIRES/SAO PAULO, Sept 6 (Reuters) - Argentine equities and the peso currency jumped on Thursday, driven by growing optimism about talks between the government and International Monetary Fund to shore up the country's finances, though traders warned the gains were fragile. Late on Wednesday, Argentina's economy minister voiced "enormous confidence" about clinching a new deal with the IMF to secure early disbursements from a $50 billion standby loan agreement approved in June. On Thursday, IMF spokesman Gerry Rice said the two sides were making progress in the talks and hoped "to conclude as rapidly as possible." The sanguine tone helped Argentina's MerVal stock index close up 4.13 percent, its second consecutive day firmly in the black, after a rocky start to the week. The peso closed up by almost 3 percent. But traders were quick to warn that any lasting improvement in the mood of the local market depended on a tangible short-term resolution to the IMF talks. "Despite some rebounds, it would be premature to interpret it as a change in the current complex environment, given that investors are still awaiting the result of the IMF negotiations," said Gustavo Ber, economist at Buenos Aires consultancy Estudio Ber. Across the region, equities markets generally posted light to moderate gains. In Brazil, traders took heart in a Thursday Supreme Court decision rejecting jailed leftist former President Luiz Inacio Lula da Silva's latest appeal to be allowed to run for president. A key poll released late on Wednesday showed his likely stand-in, Fernando Haddad, with little support, and market-friendly candidates such as centrist Geraldo Alckmin gaining ground. The Bovespa closed up nearly 1.8 percent. The index's biggest gainer was highway operator Ecorodovias Infraestrutura e Logistica SA, which climbed 8.4 percent after analysts at Morgan Stanley raised their recommendation on the stock to 'overweight' from 'underweight.' Still, there was shock in Brazil when the front-running far-right presidential candidate Jair Bolsonaro was stabbed while campaigning on Thursday, and was reported to be in a serious condition and undergoing surgery. Mexico's peso closed up more than 0.8 percent, as trade talks between the United States and Canada aimed at reworking the NAFTA trade deal continued in Washington. Key Latin American stock indexes and currencies at 2200 GMT:

Stock indexes Latest Daily YTD pct pct change

change

MSCI Emerging Markets 1,021.72 -1.77 -11.8 MSCI LatAm 2,380.08 -0.33 -15.84 Brazil Bovespa 76,416.01 1.76 0.02 Mexico IPC 48,711.85 0.24 -1.30 Argentina MerVal 29,957.50 4.13 -0.36 Colombia IGBC 11,992.39 -0.98 5.47 Chile IPSA 5,169.52 0.62 -7.10 Currencies Latest Daily YTD pct pct change

change

Brazil real 4.1042 0.95 -19.27 Mexico peso 19.1795 0.82 2.71 Chile peso 689 -0.17 -10.79 Colombia peso 3,083 0.45 -3.27 Peru sol 3.323 -0.15 -2.59 Argentina peso (interbank) 37.8000 2.86 -50.24

(Reporting by Jorge Otaola and Gram Slattery; Editing by Lisa Shumaker)