Energy stocks were edging higher premarket Friday with the Energy Select Sector SPDR Fund (XLE) up 0.1% recently.

The United States Oil Fund (USO) was down 0.2% and the United States Natural Gas Fund (UNG) was 0.5% higher.

Front-month US West Texas Intermediate crude oil was nearly 1% lower at $68.71 per barrel at the New York Mercantile Exchange. Global benchmark North Sea Brent crude oil lost 0.9% to $72.23 per barrel. Natural gas futures were up 1.7% at $3.643 per 1 million British Thermal Units.

Berkshire Hathaway (BRK.A) has increased its stake in Occidental Petroleum (OXY), purchasing about $409.2 million in shares over the last three days, a regulatory filing showed. Occidental Petroleum shares were up neearly 3% premarket.

Shell (SHEL) has made a condition of latest investments in Nigeria for approval of its oil asset sale in the Niger Delta, Financial Times reported, citing unnamed people familiar with the matter. Shell shares were 0.9% lower pre-bell.