The S&P 500 Energy index positioned itself as the highest-performing index in December 2019 with a total return of 6.0%, compared to the broad S&P 500 index's total return of 3.0% over the same period.

The S&P 500 Utilities index swung to a total return of 3.4%, compared to a total negative return of 1.8% in November 2019, according to data compiled by S&P Global Market Intelligence.

Concho Resources Inc. posted the strongest performance in the U.S. energy group with a total return of 20.7%. The Midland, Texas-headquartered company at the end of October 2019 recommended shareholders reject an unsolicited mini-tender offer from TRC Capital Corp. with an offer price below the closing share price of the company's common stock on Oct. 25.

On the December 2019 ranking, Concho was followed by Diamondback Energy Inc. with a total return of 20.1%, swinging from a negative total negative return of 9.6% the previous month. This comes shortly after S&P Global Ratings on Nov. 13, 2019, upgraded its issuer credit rating on the company to BBB- from BB+, and Fitch Ratings upgraded Diamondback's long-term issuer default rating to BBB from BBB-.

Noble Energy Inc. had the third-best return of the month at 19.7%, followed by Devon Energy Corp. with a gain of 19.1% and Pioneer Natural Resources Co. with a return of 18.8%.

The worst performer among S&P 500 Energy companies in December was Phillips 66 with a total negative return of 2.9%. During the month, the company announced a capital budget of $3.34 billion for 2020 that allocates $1.19 billion to sustaining capital and $2.15 billion to growth capital.

Valero Energy Corp. saw a total negative return of 1.9%, with its unit Valero Marketing and Supply de Mexico SA de CV recently having signed long-term agreements to use three refined product terminals in Guadalajara, Monterrey and Altamira, Mexico.

HollyFrontier Corp. and Marathon Petroleum Corp. were also among the lowest-performing S&P 500 Energy companies in December, having a negative return of 1.6% and 0.6%, respectively.

Among S&P 500 Utilities component companies, CenterPoint Energy Inc. stock returned a total of 11% in December.

Following closely was Edison International with an aggregate return of 10.1% in December. The Californian utility on Dec. 12 announced an increase of 4.08% in its quarterly dividend to 63.75 cents per share, or $2.55 per share annually.

PPL Corp. provided a 6.7% return, NiSource Inc. had a 5.3% return and AES Corp. with had a 5.2% return.

This S&P Global Market Intelligence news article may contain information about credit ratings issued by S&P Global Ratings. Descriptions in this news article were not prepared by S&P Global Ratings.