Sullivan & Cromwell has profited from Barclays Capital’s (BarCap) first major foray into the North American market through its purchase of a 40 per cent stake in Texas-based NGP Energy Capital Management, a $2.9bn (£1.52bn) private equity house focused on oil and gas production.

Managed out of the firm’s New York office, Sullivan’s team was led by tax specialist and BarCap relationship partner David Hariton and corporate partner Richard Pollack, with Don Toumey giving banking and regulatory advice.

Sullivan has a longstanding relationship with both Barclays Bank and BarCap, advising them on their Securities and Exchange Commission registration and the former’s New York Stock Exchange listing.

Corporate partner Jeffrey Zlotky at Thompson & Knight in Dallas led the advice for NGP, which will not become the US private equity arm of Barclays. BarCap hopes to exit the relationship by floating NGP in several years’ time.

BarCap head of principal investing and private equity Roger Jenkins said in a statement: “We see energy as one of the most dynamic and interesting private equity investment areas over the next 10-15 years.”

Citigroup advised Barclays, which will provide both debt and equity from its own resources.