[Editor's note: This story was updated at 1:46 p.m. Fec. 22.]

Floyd Wilson is stepping down from the Halcón Resources Corp. (NYSE: HK) management team and board to “pursue other interests,” the Houston-based company said Feb. 21.

In addition to Wilson’s departure as the company’s chairman, CEO and president, Mark Mize, executive vice president, CFO and Treasurer, and Steve Herod, executive vice president of corporate development, both resigned and will leave Halcón in the coming weeks to pursue other opportunities.

The slew of management changes at Halcón follows calls for a sale of the company made earlier this month by activist investor Fir Tree Partners.

RELATED: Activist Investor Threatens Halcón Resources With Proxy Fight 

Fir Tree, which owns about 7.2% of Halcón, had said Feb. 4 that if the company did not cut expenses and appoint new board members, it may run a proxy contest at the next annual general meeting to replace its entire board.

On Feb. 22, Fir Tree commented on Halcón’s management and board changes but also renewed its call for the sale of the company.

“We are encouraged that Halcón is following our recommendations by enacting changes at the senior management and board level and significantly reducing G&A–with a particular focus on cutting excessive executive compensation costs. In our view, these are important first steps towards realizing increased value for the company’s shareholders and we commend the board for these actions,” the firm said in a statement. “However, we continue to believe that there is more work to do to maximize shareholder value, which is highlighted by Halcón’s stock trading down since this announcement.”

The firm added that it believes Halcón has “an ideal opportunity at this point to initiate a sale process.”

During Wilson’s tenure, Halcón transformed itself into a Delaware Basin-focused independent energy company, shedding assets in the Bakken and Eagle Ford shale plays.

Wilson said in a statement: “Leading Halcón for the past seven years alongside a great management team has been a privilege and I am proud of the efforts of all of our employees. I’m confident a platform is in place that will allow the company to move forward with profitable growth and value creation.”

James Christmas has been appointed non-executive chairman of the board. He has served as a director of Halcón since February 2012 and also serves as lead independent director and chairman of the audit committee.

The Halcón board will commence a search process for a permanent CEO, according to the company release.

In the interim, Halcón will be managed by a management committee led by David Elkouri, executive vice president and chief legal officer, which will report to  Christmas.

“Our board is focused on pursuing a strategy to enhance profitability and increase shareholder value through disciplined cost management and operational improvements,” Christmas said in a statement. “Halcón’s management team will have a renewed focus on reducing costs at all levels and optimizing development of Halcón’s outstanding acreage with an emphasis on managing drilling and completion costs to maximize rates of return.”