EMERGING MARKETS-Chilean stocks outperform Brazil, Mexico

* Mexico's IPC down 0.1 pct, Bovespa falls 0.5 pct

* Petrobras stock tumbles ahead of share offering

* Chile's IPSA reaches new intraday high

(Updates to close)

By Caroline Stauffer and Alvaro Tapia

MEXICO CITY/SANTIAGO, Sept 8 (Reuters) - Brazilian stocks fell on Wednesday, dragged down by losses in state oil company Petrobras, while Chilean stocks reached a new intraday high boosted by banks and airlines.

The MSCI Latin American stocks index .MILA00000PUS fell 0.19 percent. Brazil's Bovespa .BVSP closed down 0.51 percent, as Petrobras investors scrambled to position themselves in front of a share offering.

Chile's blue-chip IPSA index .IPSA closed with gains of 1.30 percent. The Chilean central bank raised its economic growth forecast on Wednesday. [ID:nN08111039].

"The market has behaved optimistically, in line with the dynamism shown by the economic data," said Mario Arend, an economist at Celfin Capital in Santiago.

The Chilean market touched a new intraday high of 4,647 points.

Shares in Banco Santander Chile STG.SN rose 2.24 percent while Banco de Chile CHI.SN gained 2.21 percent.

Lan Airlines LAN.SN rose 1.5 percent as U.S. investors bought positions awaiting the approval of a merger with Brazilian carrier TAM TAMM4.SA(TAM.N).

The airline said on Wednesday its passenger traffic rose 13.7 percent in August from a year earlier. [ID:nN08131538]. Mexico's IPC stock index .MXX showed slight losses of 0.12 percent to close at 32,4010.

Shares in Telecom giant American Movil (AMXL.MX), owned by billionaire Carlos Slim, shed 0.62 percent, but top retailer Wal-Mart de Mexico (WALMEXV.MX) rose 0.81 percent while base metals miner Penoles (PENOLES.MX) gained 1.68 percent.

PETROBRAS DOWN

Preferential shares in Brazilian oil giant Petrobras (PETR4.SA) shed 4.33 percent while ordinary shares (PETR3.SA) tumbled 4.44 percent ahead of a huge capitalization deal.

In recent sessions, investors had rushed to buy Petrobras stock before Monday's deadline so they would be in a privileged position to participate in the upcoming share offering.

Now that deadline has passed and the same investors are trying to push down the share price when the offering eventually takes place later this month, Renato Tavares at Brazil's Intrader Investimentos said.

Shares in Brazil's mining giant Vale (VALE5.SA)(VALE.N) lost 1.88 percent. The company said on Wednesday it plans to issue 10-year bonds in international capital markets. [ID:nN0885955]. (Reporting by Caroline Stauffer in Mexico City, Alvaro Tapia in Santiago and Aluisio Alves in Sao Paulo, Editing by Chizu Nomiyama and Editing by Andrew Hay)