Whiting Petroleum Corp (WLL.N), North Dakota's largest oil producer, is seeking a possible buyer, according to the Wall Street Journal, but a person familiar with the board's thinking told Reuters he was not aware of any such plan.

The Denver-based company began seeking a buyer after tumbling crude oil prices CLc1 eroded its market value, the Journal reported earlier on Friday, citing people familiar with the matter.

Three months ago, Whiting closed on its $1.55 billion buyout of Kodiak Oil & Gas to become the largest oil company in North Dakota, home to the Bakken shale formation, one of the world's largest crude reserves.

Clinching Kodiak helped Whiting eclipse rival Continental Resources Inc (CLR.N), guaranteeing years of growth potential and access to even more lucrative acreage across North Dakota, the No. 2 U.S. oil producing state.

Although the deal increased the company's debt by nearly $3 billion, Moody's (MCO.N) upgraded Whiting's bond rating in December, citing the deal's ability to cut costs to drill and produce oil.

Whiting posted a lower-than-expected quarterly profit last month and slashed its 2015 budget, thanks largely to cheap oil prices that have stressed the entire energy industry. The company's stock has dropped 60 percent in the past six months.

But Chief Executive Jim Volker told Wall Street he remains bullish, stressing Whiting would not delay hydraulic fracturing of new wells - a costly step amid cheap oil prices but one designed to keep oil, and revenue, flowing.

"We remain confident in our outlook for continued growth," Volker said on Feb. 26.

Only one of the 33 Wall Street analysts covering the company recommend that investors sell shares, according to Thomson Reuters data.

A second person close to Whiting's management said any sale now, with the company just having taken the top spot in the Bakken, would not make sense. The source added that while Volker is 67, past the traditional age of retirement, Berkshire Hathaway (BRKa.N) CEO Warren Buffett is still working at 84, a comparison meant to show that Volker has no plans to step aside from the company where he has worked since 1983.

Both sources spoke to Reuters on the condition of anonymity so they could comment freely about market speculation on matters that have not been made public.

A Whiting spokesperson was not immediately available to comment.