NEW YORK (TheStreet) -- Shares of Petrobras (PBR.A) are down 1.2% to $5.76 in afternoon trading today as oil prices decline.

Brent fell 2.58% to $57.66 at 1:14 p.m. in New York. West Texas Intermediate was down 3.19% to $49.79.

Oil reversed gains from yesterday, falling today as fears about the disruption of Middle East crude shipments from Yemen's conflict eased, and focus turned to the likelihood of an Iranian nuclear deal by next week that could ultimately lead to even more supply on the market, Reuters reports.

Also, the Brazilian state-run oil firm said today that it has nominated the chief executive of mining giant Vale (VALE) - Get Report, Murilo Ferreira, as its next board chairman, as the company continues to make changes amid scrutiny from a widespread corruption scandal, the Wall Street Journal reports.

Adding pressure to the stock, Brazilian construction firm Galvao Engenharia filed a request for bankruptcy protection yesterday, the second such filing by a company alleged by authorities to have been involved in corruption with the state-run energy giant, the Journal said.

Investors are reportedly buying debt issued by Petrobras, reversing a long decline in the price of its bonds amid expectations that it could soon resolve uncertainty over its financial statements, the Journal noted.

Insight from TheStreet's Research Team

Tim Melvin commented on Petrobras in a recent post on RealMoney.com. Here is what Melvin had to say about the stock:

Each year I have read [the Bain & Co. private equity report], I find it incredibly useful as a guide to opportunities in certain sectors and regions of the world... This year's report highlights Brazil and some of the opportunities that may be available in that troubled nation. I have held some Brazilian stocks for a couple of years now and it has been a bumpy, unpleasant journey so far. Over my holding period, we have gone from "this looks like maximum pessimism" to "maybe they will vote her out and jumpstart things" to "you have got to be kidding me." We have seen widespread corruption involving Petrobras, continued weakness in the economy and, just this weekend, protestors taking to the streets to demand the impeachment of the president the country just reelected. Brazil is a mess and it's not getting better anytime soon.

- Tim Melvin, 'Prospecting in 2 Troubled Economies' originally published 3/18/2015 on RealMoney.com.

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Separately, TheStreet Ratings team rates PETROLEO BRASILEIRO SA- PETR as a Hold with a ratings score of C-. TheStreet Ratings Team has this to say about their recommendation:

"We rate PETROLEO BRASILEIRO SA- PETR (PBR.A) a HOLD. The primary factors that have impacted our rating are mixed, some indicating strength, some showing weaknesses, with little evidence to justify the expectation of either a positive or negative performance for this stock relative to most other stocks. The company's strengths can be seen in multiple areas, such as its revenue growth, largely solid financial position with reasonable debt levels by most measures and attractive valuation levels. However, as a counter to these strengths, we also find weaknesses including disappointing return on equity, weak operating cash flow and poor profit margins." You can view the full analysis from the report here: PBR.A Ratings Report