Papua New Guinea's biggest company Oil Search Ltd. said on Oct. 1 long-serving managing director Peter Botten will retire from the firm next year after 25 years in the role.

He will be succeeded by senior executive Keiran Wulff in February and will step down from the board on Aug. 25, 2020.

"Under his (Botten's) leadership, Oil Search has grown from a small exploration and production company to a regionally significant oil, gas and LNG producer and exporter," Oil Search chairman Rick Lee said in a statement.

Wulff, currently Oil Search's executive vice president, Alaska and president of Oil Search Alaska, was appointed chief executive officer designate.

"The board has agreed unanimously that Dr. Wulff is the best person to succeed Peter, with the necessary experience, leadership skills and vision to take Oil Search into the future," the company said.

Botten is stepping down at a crucial time for the company as its larger partners in two liquefied natural gas (LNG) projects in Papua New Guinea, Total SA and Exxon Mobil Corp., look to push through a $13 billion plan to expand gas exports.

"It's pretty big shoes to fill. [Wulff] was the most logical candidate. He's certainly well regarded," said Andy Forster, senior investment officer at Argo Investments, which owns Oil Search shares.

The company is also in the midst of expanding its Alaska operations, which Wulff has led, after acquiring assets on North Slope two years ago and has recently doubled its stake there.

Botten will continue his association with the company and PNG through his roles as chairman of the Oil Search Foundation and the Hela Provincial Health Authority and as a member of the Australia Papua New Guinea Business Council Executive Committee.