* Brazil's Petrobras shares drop on scandal speculation
* Investors brace for U.S. payrolls data on Friday
* Mexico's IPC down 0.33 pct, Bovespa dips 0.88 pct (Adds Net stock move, updates prices, adds quote)
By Luciana Lopez and Ana Nicolaci da Costa
SAO PAULO, Oct 7 (Reuters) - Latin American stocks slipped on Thursday as worries over a possible scandal involving Petrobras dragged down shares in the oil giant, while investors braced for U.S. jobs numbers on Friday.
The MSCI Latin American stocks index <.MILA00000PUS> dropped 0.69 percent.
In Brazil, shares of state-controlled energy company Petrobras sank, extending a steep tumble in the previous session.
The company's preferred shares, its most widely traded
stock
(For graphics on Petrobras, see
http://link.reuters.com/qec25p)
Market sources consulted by Reuters said the shares were down both on the effect of the share offering and rumors that weekly news magazines were preparing to reveal information that could spark a corruption scandal.
"In addition to the (share offer), there has been speculation a scandal involving Petrobras and the (Workers' Party) could be released in weekly magazines," said Erick Scott of the brokerage SLW Corretora.
A spokesman for the ruling Workers' Party said it does not comment on speculation. A Petrobras spokesman said the company had no comment.
But a strategist who asked not to be named was dismissive of the talk.
"I think the fears are exaggerated," the strategist said. "I don't think anyone was really hip deep in it."
Corruption scandals are common during electoral campaigns in Brazil, where voters will choose the country's next president in a runoff vote on Oct. 31.
Petrobras's common and preferred stock, which together make up nearly 15 percent of the MSCI Latin American stocks index, recorded their worst one-day tumbles in more than a month in the previous session as analysts cut their recommendations. For details, see [ID:nN06266509]
Bucking the trend, Net Servicos
U.S. PAYROLLS EYED
Uncertainty ahead of U.S. non-farm payrolls data due on Friday also weighed on regional markets.
Data on Thursday showed new claims for U.S. unemployment benefits unexpectedly fell last week to the lowest in nearly three months. But this did little to change perceptions that the world's largest economy is struggling to produce jobs.
"Since there is uncertainty, there is no clear trend to the upside or to the downside ... investors tend to be cautious, they tend to reduce positions that could lead to losses, in case the number is not that good," said Raphael Martello, economist at Tendencias.
Brazil's benchmark Bovespa stock index <.BVSP> was down 0.88 percent, with Petrobras leading losses.
Steelmakers also dropped as shares of Gerdau
Deutsche Bank analyst Rodrigo Campos lowered his recommendation for Gerdau and Usiminas to "hold" from "buy," citing pressure on profit margins stemming from declining prices for some steel products in the local market. [ID:nN07257781]
Mexico's IPC index <.MXX> dropped 0.33 percent after notching record-high closes in the previous two sessions.
"The market is resting after achieving historical highs, awaiting U.S. payrolls data (Friday) and the beginning of earnings season in Mexico next week," said Carlos Ponce, head of analysis at brokerage IXE in Mexico City.
Wal-Mart de Mexico
Chile's IPSA index <.IPSA> dropped 1.18 percent, heading for four straight days of declines for the first time since May as analysts pointed to technical levels triggering a sustained correction. (Additional reporting by Guillermo Parra-Bernal in Sao Paulo; Caroline Stauffer in Mexico City, Brad Haynes in Santiago and Denise Luna in Rio de Janeiro; Editing by Gary Crosse and Dan Grebler)