ArcLight Capital Partners has acquired a 25% interest in the Kinder Morgan-operated (KMI) Natural Gas Pipeline Company of America, or NGPL, giving it majority ownership of the pipeline system.

ArcLight now owns 62.5% of NGPL, while Kinder Morgan retains a 37.5% stake, ArcLight said Tuesday.

Terms of the transaction were not disclosed.

NGPL is one of the largest interstate pipeline systems in the country, spanning 9,100 miles across nine states, according to the statement.