NEW YORK (TheStreet) -- Shares of Marathon Oil (MRO) - Get Report are down by 1.48% to $27.34 in mid-morning trading on Monday, as some energy and related stocks fall today along with the price of oil.

The commodity is being driven lower by the latest development regarding the Greek debt crisis. The country has closed banks and issued capital controls, causing investors to run from riskier assets and weakening demand outlook, Reuters reports.

Talks between the debt-riddled country and its international creditors on Saturday came to a halt when Greece's Prime Minister Alexis Tsipras announced he is calling for a referendum on July 5.

The referendum is essentially a vote on measures its creditors have demanded in return for more bailout funds, The Wall Street Journal reports.

Crude oil (WTI) is lower by 1.485 to $58.75 per barrel and Brent crude is slipping by 1.55% to $62.28 per barrel this morning, according to the CNBC.com index.

"This may be the time when we break lower and into the $50s for Brent as we have a full week of uncertainty," SEB head of commodity analysis Bjarne Schieldrop told Reuters.

Insight from TheStreet Research Team:

TheStreet's Jim Cramer, Portfolio Manager of the Action Alerts PLUS Charitable Trust Portfolio and Jack Mohr, Director of Research-Action Alerts PLUS, commented on Marathon Oil in a post today on Action Alerts PLUS. Here is a snippet of what Cramer and Mohr had to say:

We believe MRO's attractive shale acreage and efficient drilling program should help drive outsized growth while generating ample cash flow over the coming years.

The company's best-in-class management team has displayed a disciplined spending approach, successful cost-control, effective allocation and willingness to divest non-core assets for cash. (Thereby boosting its balance sheet).

-Jim Cramer and Jack Mohr, 'Initiating New Position in Energy Name' Originally Published on 06/29/2015 on Action Alerts PLUS.

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