Energy stocks were declining premarket Monday as the Energy Select Sector SPDR Fund (XLE) was down 0.5% recently.

The United States Oil Fund (USO) was up 0.4% and the United States Natural Gas Fund (UNG) was 2.9% lower.

Front-month US West Texas Intermediate crude oil was up 0.4% at $67.26 per barrel at the New York Mercantile Exchange. Global benchmark North Sea Brent crude oil gained 0.9% to $68.93 per barrel, and natural gas futures were 2.1% lower at $3.34 per 1 million British Thermal Units.

Shell (SHEL) shares were down more than 2% after the company tightened its Q2 production outlook for integrated gas and LNG businesses, warning that trading and optimization is expected to be "significantly lower" than Q1.