EMERGING MARKETS-Latam stocks rise, led by Brazil, Chile

* Bovespa leads Latin American markets higher, up 1 pct

* Petrobras gains 1.3 pct, after unveiling oil reserves

* Chile's IPSA rises 0.8 pct, Argentina's Merval up 1 pct

SAO PAULO, Dec 29 (Reuters) - Latin American stocks headed for their biggest one-day advance in more than a week on Wednesday, led by gains in Brazilian and Chilean markets.

The MSCI Latin American stocks index .MILA00000PUS rose 1.1 percent, up for a second straight session and on track for its biggest jump since a 1.6 percent rise on Dec. 21.

Brazil's benchmark Bovespa index .BVSP climbed 1 percent to 68,709.31, led by steelmaker Usiminas, state-run oil giant Petrobras and real estate developers.

Petrobras (PETR4.SA) gained 1.3 percent to 27 reais. The company said its reserves rose by 8.3 billion barrels of oil equivalent after two massive oil fields in the deep waters offshore region known as the subsalt were declared commercially viable. For details, see [ID:nN29276917]

"This week has had very good news flow for the company," said Rafael Dornaus, a stock trader at the Hencorp Commcor brokerage, citing the news about the Lula and Cernambi fields.

Steelmaker Usiminas (USIM5.SA) jumped 2.1 percent to 18.69 reais after it said late Tuesday it had concluded a deal to sell a 30 percent stake in its Mineracao Usiminas SA mining unit to Japan's Sumitomo Corp for up to $1.93 billion. it will the funds to sharply expand iron ore output.

Brazilian real estate developers PDG Realty (PDGR3.SA) rose 1.7 percent to 10.12 reais, while Rossi Residencial (RSID3.SA) was up 2.4 percent to 14.43 reais. Dornaus said better-than-expected wholesale inflation figures boosted the sector as they eased concern about higher borrowing costs in the months ahead.

Brazil Hospitality Group (BHGR3.SA), a hotel operator controlled by private equity firm GP Investments that is not part of the Bovespa index, jumped 2.6 percent to 19.09 reais. The company agreed late Tuesday to buy smaller rival Brascan Imobiliaria Hotelaria e Turismo SA, which owns the building for the Intercontinental Hotel Rio de Janeiro. Brazil Hospitality is looking to boost its presence in cities with great potential for business travel.

Chile's IPSA .IPSA jumped 0.8 percent to 4,869.58, heading for its biggest daily gain in more than one month. Retailers Cenconsud CEN.SN and Falabella FAL.SN led the index higher, rising 2 percent and 1.5 percent, respectively.

In Argentina, the benchmark Merval index .MERV jumped 0.9 percent to 3,527.6, extending a rally that has pushed it up by 2.5 percent over five straight sessions.

Steelmaker Tenaris (TENA.BA) led the gains, up 1 percent, while financial conglomerate Grupo Financiero Galicia (GFG.BA) also added 1 percent. (Reporting by Elzio Barreto and Silvio Cascione; editing by Jeffrey Benkoe)