Middle market investment firm Capstone Partners has hired Brad Stewart and Brent Krambeck as managing directors for its Debt Advisory Group, significantly expanding the leadership team and making it one of the largest debt capital advisory teams in the middle market, according to the firm.

Stewart, who is based in the Boston headquarters of Capstone, brings more than 20 years of debt financing experience to the firm, having been previously a Partner at debt advisory firm Capital Solutions Group and, prior to that, was in the debt capital markets group at Audax Private Equity.

Based in Chicago, Krambeck has more than two decades’ experience advising, structuring, and executing middle market debt transactions for private equity sponsors, small cap public, and private companies. Krambeck was previously Managing Partner at Monroe Credit Advisors.

“With a contracted credit market, inquiries for debt placement services have increased dramatically,” said Brendan Burke, head of sponsor coverage at Capstone Partners. “We are investing in the expansion of our debt capital advisory team to meet that need for our private equity clients.”

Capstone’s Debt Advisory Group offers capital solutions in the debt markets, assisting clients secure debt capital or leveraged finance for acquisitions, scaling organic growth and refinancings.

Boston-based Capstone’s services include M&A advisory, debt and equity placement, corporate restructuring and special situations, among others.