Continental Resources Inc. President and COO Rick Bott resigned on Thursday to “pursue other opportunities,” the Oklahoma City-based operator announced. It was news that was unexpected by the market.

Bott’s duties are to be absorbed by senior management, said CEO Harold Hamm. Bott, 54, was considered to be next in line to succeed Hamm, who is 68. Hamm said the company was grateful for Bott’s contributions.

Attempts to contact Bott were not successful, and there was no information about whether he was moving to another company. He previously worked for Cairn India Ltd. and also was an executive in Devon Energy Corp.’s international division.

As part of his severance package with Continental, Bott is to receive $581,000, as well as $23,600 for unused sick leave. He also would be able to participate in the 2014 bonus program and have early access to 50,00 shares of unrestricted stock that were not set to vest until December. Continental was trading down at about $74.19/share at mid-morning Friday.

Bott over the past few months has been making the rounds at the industry conferences to promote the company, which is the largest producer in the Bakken Shale. The company is one of the leading oil operators in the U.S. onshore, with a market cap of about $27.36 billion.

In his statement to announce Bott’s resignation, Hamm said Continental is ahead of its five-year plan to triple production and proved reserves from 2012 to 2017. “Continental continues on the dynamic path that we have followed for nearly half a century, and the best is yet to come,” he said.