Two Barclays Plc investment bankers have been hired away by Pickering Energy Partners as the Houston-based firm expands its upstream oil and gas investment banking business.

Robyn Underwood and Jason Kivett, both managing directors in Barclays’ Houston office, are leaving the London-based bank for Pickering, according to people familiar with the matter. A Pickering representative declined to comment. A representative of Barclays said in an emailed statement that the firm announced a new investment banking leadership team in the first quarter and “we expect and plan for natural attrition when changes occur.”

Pickering Energy Partners, founded by prominent shale financier Dan Pickering, has focused on energy-transition investment and research for years. Now it’s pushing harder into oil and gas and hiring to expand its capacity to advise corporations on mergers and acquisitions. Pickering also invests in both public and private energy companies, deploying more than $16 billion since 2004.

The departures from Barclays come as a slew of bankers have recently left the firm’s New York office. The London-based lender recently lost three senior dealmakers to Jefferies Financial Group Inc., while UBS Group AG hired away a half-dozen technology, media and telecommunications bankers.

Read More: Barclays CEO Addresses Dealmaker Exits in Virtual Town Hall

Bobby Tudor — who teamed with Pickering to finance the US shale boom at Tudor, Pickering, Holt & Co. — recently launched his own Houston firm, Artemis Energy Partners.

--With assistance from David Wethe and Rachel Butt.

(Updates with Barclays statement in second paragraph)