Devon Energy Corp said on Aug. 3 that chief operating officer Dave Hager was named chief executive officer, taking over for John Richels, 64, who is retiring.

Hager takes the helm of Devon at a challenging time in the industry. Crude oil prices have fallen by more than half from a year-ago high of more than $100 a barrel and companies are having to slash spending and cut jobs to preserve cash in the downturn.

Hager's appointment as CEO and president became took effect on Aug. 1. Hager, 58, joined the Oklahoma City, Oklahoma-based company in 2009 as head of exploration and production.

The company's succession plans were announced in December.

Shares of Devon, which focuses solely on oil and gas exploration and production onshore in North America, were down 1 percent at $48.91 in morning New York Stock Exchange trading, mirroring a 1 percent slide in crude.