Carl Icahn, the activist shareholder who spurred Aubrey McClendon's downfall at Chesapeake Energy Corp., in early October bought a

6% stake in Canada's Talisman Energy. Icahn revealed on his Twitter account that he had “disclosed [an] approximately 61-million-share position in Talisman Energy. [I] may have conversations with management [about] strategic alternatives, board seats, etc.”

Icahn's shares in the company were acquired “in the belief that they were undervalued relative to the value of the issuer's underlying assets,” according to a Securities and Exchange Commission filing.

The filing states that Icahn intends “to have conversations with members of the [Talisman's] management to discuss strategic alternatives that may enhance shareholder value, including, among other things, asset sales or potential corporate restructuring.” It said he may discuss shareholder board representation.

Talisman did not address Icahn's stake directly, but said in a statement that it is “committed to acting in the best interests of the company and give due consideration to constructive recommendations for strategies or actions that have the potential to increase shareholder value,” Reuters reported.

Icahn, a billionaire who started his career as a registered representative with Dreyfus & Co. and bought a seat on the New York Stock Exchange in 1968, is often brash. His Twitter account features the quote, “Some people get rich studying artificial intelligence. Me, I make money studying natural stupidity.”

In the 1980s, he was described as “one of the most feared corporate pirates” by the Chicago Tribune, having gone after Phillips Petroleum and other companies. In 2013, months after Icahn acquired a stake in Transocean Ltd., the offshore driller's chairman and former chief executive agreed to step down before a proxy fight. Icahn Capital LP retains a seat on the company's board.

The end of McClendon's tenure as head of Chesapeake can be traced back to Icahn's call in May for McClendon to be replaced as board chairman. Icahn viewed McClendon's use of his position to secure more than $800 million in private loans as inappropriate.

John P. Herrlin Jr., head of Société Générale's oil and gas equity research, says that while Icahn can “pick on management for mismanaging … the company is actually trying to make efforts to change already.”

For instance, the company is trying to sell its Ocensa pipeline in Colombia and has opened data rooms to either rationalize or reduce exposure to assets with longer project cycle times in Norway and in Canada's Montney and North Duvernay shales.

It is refocusing on North America and Asia and away from the North Sea. In its second quarter of this year, the company posted growth in the Eagle Ford, but the start-up of its offshore Vietnam drilling was offset by turnarounds and downtime in the North Sea. “In short, TLM remains a work in progress,” Herrlin says.

—Darren Barbee