(Updates prices) SAO PAULO, June 8 (Reuters) - Brazilian equities extended their recent slide amid political and fiscal worries on Friday, while Mexican stocks and currency advanced.

Stocks on the benchmark Bovespa stock index tumbled across the board for a fourth straight session, as traders continued to fret ahead of an unpredictable October election in which market-friendly candidates have failed to gain traction, according to recent polls.

Recent government intervention in oil company Petroleo Brasileiro SA has also caused traders to question the resolve of the current government - and the ability of the next one - to stay on a path of pro-market policies and relative fiscal austerity.

"It's still an uncertain scenario, without a positive conclusion coming to light for local financial markets," said a Rio de Janeiro-based trader.

The Bovespa index was down 1.23 percent in late morning trade, after falling almost 3 percent earlier in the session.

After a punishing week for the Mexican peso, the currency recovered on Friday, up 1.06 percent in afternoon trading. Investors are closely watching the Group of Seven summit in Canada and were encouraged by the fact that U.S. President Donald Trump did not intensify his rhetoric on trade, analysts said.

Mexico's benchmark index IPC was up 1.02 percent in afternoon trading.

In neighboring Argentina, the peso fell sharply against the dollar after the country signed a $50 billion standby financing arrangement with the International Monetary Fund, causing the central bank to abandon its spirited defense of the currency.

"I think (the) USD/ARS upward trend should remain intact," said Win Thin, Global Head of Emerging Market Currency Strategy at Brown Brothers Harriman in New York.

"Once the IMF deal was reached in principle, I'm sure that Argentina was asked to take FX intervention off the table. Last thing the IMF wants to see is its program money burned away by FX intervention." The Argentine peso was down 1.25 percent at 25.3 per dollar in late afternoon trading.

Key Latin American stock indexes and currencies at 2015 GMT: Stock indexes Latest Daily YTD pct pct change change MSCI Emerging Markets 1,137.69 -1.04 -0.76 MSCI LatAm 2,510.55 2.5 -13.39 Brazil Bovespa 72,942.07 -1.23 -4.53 Mexico IPC 45,939.54 1.02 -6.92 Chile IPSA 5,510.67 0.78 -0.97 Chile IGPA 27,885.75 0.79 -0.34 Argentina MerVal 31,454.66 4.23 4.62 Colombia IGBC 12,251.57 -0.09 7.75 Venezuela IBC 40,543.53 1.71 3,109.74 (Reporting by Gram Slattery; additional reporting by Paula Arend Laier in Sao Paulo, Rodrigo Campos in New York, and Sheky Espejo; editing by G Crosse and Diane Craft)