13D Filing: Corvex Capital and Energen Corporation (EGN)

The percentage calculated in the immediately foregoing paragraph is calculated based on a total of 97,188,418
Shares outstanding as of May 1, 2017, as reported in the Issuers Quarterly Report on Form 10-Q filed with the SEC on May 9, 2017.

On June 26, 2017, Corvex exercised over-the-counter market American-style
call options with an expiration date of May 31, 2018, referencing an aggregate of 5,508,364 Shares at an exercise price of $36.50 per Share (which resulted in the termination of corresponding over-the-counter market European-style put options referencing an aggregate of 5,508,364 Shares at an exercise price of $36.50 previously sold by Corvex).

In addition, Corvex has acquired listed American-style call options referencing an aggregate of 415,200 Shares, which have an exercise price of $50 per Share
and expire on October 20, 2017. Corvex also has sold listed American-style call options referencing an aggregate of 415,200 Shares at an exercise price of $60 per Share, which expire on October 20, 2017, and has sold listed American-style
put options referencing an aggregate of 415,200 Shares at an exercise price of $40 per Share, which expire on January 19, 2018.

(c) Except as set
forth in Exhibit 5 attached hereto or previously disclosed in the Schedule 13D, as amended, there have been no transactions in the Shares during the sixty days prior to the date hereof by any of the Reporting Persons.

(d) The limited partners of (or investors in) each of the private investment funds for which Corvex or its affiliates acts as general partner and/or
investment adviser have the right to participate in the receipt of dividends from, or proceeds from the sale of, the Shares held for the accounts of their respective funds in accordance with their respective limited partnership interests (or
investment percentages) in their respective funds.

(e) Not applicable.

Item 7. Material to be Filed as Exhibits

Exhibit 4
Letter to the Board of Directors of Energen Corporation, dated June 27, 2017

Exhibit 5 Transactions in the Shares effected in the past
60 days