NEW YORK (TheStreet) -- Shares of Whiting Petroleum (WLL) - Get Report were falling 2.9% to $29.61 Monday as oil prices fell after rebounding late last week.

WTI crude oil for May delivery was down 1.2% to $48.28 a barrel early Monday afternoon, and Brent crude oil for May delivery was down 1.5% to $55.56 a barrel.

Oil prices were falling as six world powers and Iran were discussing a possible deal over Iran's nuclear program that would lead to the end of sanctions on Iranian oil exports, according to Reuters. The countries have until Tuesday to reach an agreement, and it is expected the talks will end with some sort of agreement in place, according to the news service.

"Further downward pressure may come at any time from a nuclear agreement with Iran," Societe General analyst Michael Wittner told Reuters. "If a framework agreement is reached, we would expect an immediate bearish knee-jerk reaction in the markets, with oil prices quickly losing on the order of $5."

Insight from TheStreet's Research Team:

Whiting Petroleum is a core holding of David Peltier's Stocks Under $10 Portfolio. During the most recent weekly roundup, this is what Dave had to say about the stock: 

Whiting Petroleum (WLL; $30.50; 2.12%; Inflection Point; $51 price target): Whiting explores for oil and gas in the Permian Basin, Williston Basin and Green River Basin. The stock dropped 21% this week, as management sold $1 billion of stock and nearly $2 billion of new debt on Tuesday. We believe the strategy makes strategic sense, although it came at a high cost. We believe the company can continue to post solid production growth in the coming quarters.

-David Peltier, "Stocks Under $10 Weekly Roundup," originally published 3/27/15 on TheStreet.com/StocksUnder$10

Separately, TheStreet Ratings team rates WHITING PETROLEUM CORP as a Hold with a ratings score of C-. TheStreet Ratings Team has this to say about their recommendation:

"We rate WHITING PETROLEUM CORP (WLL) 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. Among the primary strengths of the company is its expanding profit margins over time. At the same time, however, we also find weaknesses including a generally disappointing performance in the stock itself, feeble growth in the company's earnings per share and deteriorating net income."

Highlights from the analysis by TheStreet Ratings Team goes as follows:

• Despite the weak revenue results, WLL has outperformed against the industry average of 19.9%. Since the same quarter one year prior, revenues slightly dropped by 4.3%. Weakness in the company's revenue seems to have hurt the bottom line, decreasing earnings per share.
• The gross profit margin for WHITING PETROLEUM CORP is currently very high, coming in at 71.37%. Regardless of WLL's high profit margin, it has managed to decrease from the same period last year. Despite the mixed results of the gross profit margin, WLL's net profit margin of -52.00% significantly underperformed when compared to the industry average.
• Net operating cash flow has declined marginally to $466.00 million or 5.01% when compared to the same quarter last year. Despite a decrease in cash flow of 5.01%, WHITING PETROLEUM CORP is in line with the industry average cash flow growth rate of -13.05%.
• WHITING PETROLEUM CORP has experienced a steep decline in earnings per share in the most recent quarter in comparison to its performance from the same quarter a year ago. Earnings per share have declined over the last two years. We anticipate that this should continue in the coming year. During the past fiscal year, WHITING PETROLEUM CORP reported lower earnings of $0.80 versus $3.07 in the prior year. For the next year, the market is expecting a contraction of 168.8% in earnings (-$0.55 versus $0.80).
• The company, on the basis of change in net income from the same quarter one year ago, has significantly underperformed when compared to that of the S&P 500 and the Oil, Gas & Consumable Fuels industry. The net income has significantly decreased by 496.8% when compared to the same quarter one year ago, falling from -$59.27 million to -$353.68 million.
• You can view the full analysis from the report here: WLL Ratings Report