Call it the Petrobras effect: The planned sale of $75 billion—whoops, hold that—yesterday Petrobras announced it would sell an additional $6 billion–in stock by Petrobras (PBR) is weighing down the entire Brazilian stock market.

And statements like this by Jeff Lu, who manages the biggest investment fund in china, China Asset Management, sure don’t help: The offering is “not very attractive,” Lu told Bloomberg. “The profitability is not very great.”

It wouldn’t be easy to get global financial markets to swallow $81 billion in stock in any case. (The $81 billion includes $42.5 billion in shares that the company will use to pay the government for 5 billion barrels of undeveloped offshore oil reserves from the Brazilian government.)

And digesting a deal of this size isn’t made any easier by investors’ suspicion that Petrobras will have to come back to the well not so far in the future. The company estimates that it will need to finance $224 billion in investments through 2014.

But the biggest hurdle may turn out to be the company’s lagging profitability. In the second quarter Petrobras posted the smallest profit increase of any of the top 10 oil companies—with the exception of BP. And I’m pretty sure that beating out BP isn’t on anyone’s list of a major achievement.

The lagging profit growth at Petrobras is a reminder that there are disadvantages to being the biggest oil company in Brazil. Thanks to government caps on fuel prices, Petrobras, which has a huge but low profit refinery business, wasn’t able to pass along rising oil prices to buyers at the pump.

But the drag that Petrobras is currently exerting on the prices of Brazilian stocks in all sectors has actually created a decent buying opportunity in stocks other than Petrobras. Iron-ore giant Vale (VALE), for example, is down since it climbed to $28.37 in the September 1 rally. The stock currently trades at $27.86.

Keep your eyes open for Brazilian bargains as the Petrobras sale gets closer. (The offering is set to price on September 23.) Other stocks I’d watch for evidence of the Petrobras effect are Itau Unibanco (ITUB), Banco Bradesco (BBD), and airline Gol Linheas Aereas (GOL).