Willow Tree Capital Taps Adviser’s Finance Chief Siddhartha Chowdhury as Its CFO Mark Klingensmith Steps Down

Siddhartha Chowdhury moves up from Willow Tree Credit Partners barely a month after joining there, taking the books of a lender whose portfolio has grown past $920 million.

September 2, 2026

Willow Tree Capital Corporation has replaced its chief financial officer, elevating an executive who joined the manager’s platform only weeks earlier.

Mark Klingensmith notified the middle-market lender on August 31 that he was resigning as chief financial officer and treasurer, effective September 1. The company said the departure did not stem from any disagreement over its operations, policies or practices. The board named Siddhartha Chowdhury, 51, to both posts on September 1, filling the vacancy the same day it opened.

An internal promotion, not an outside search

Chowdhury arrives from inside the Willow Tree organization. He joined Willow Tree Credit Partners LP, an affiliate of the business development company’s investment adviser, as its chief financial officer in August 2026, putting him at the manager for roughly a month before taking on the fund’s books. He brings close to 25 years of public and private accounting experience:

• 12 years at Audax Private Debt, the middle-market credit manager, most recently as executive vice president;
• a master of commerce in accountancy and a master of applied finance from the University of Wollongong, and a bachelor of commerce in accountancy from St. Xavier’s College, Calcutta;
• certified public accountant licenses in both Massachusetts and Australia.

A clean break between reporting periods

The handoff falls between quarters. Klingensmith certified the company’s second-quarter report on August 12, roughly three weeks before giving notice, which leaves Chowdhury to sign his first certification for the September quarter rather than inheriting a period he did not oversee.

A growing book behind the finance seat

Willow Tree Capital is a Maryland corporation regulated as a business development company under the Investment Company Act of 1940, and it lends primarily through floating-rate senior secured loans to middle-market borrowers. The portfolio carried roughly $921.5 million of fair value across 60 borrowers at June 30, up from about $884.4 million across 54 companies at the close of 2025. Net investment income had already stepped up sharply in the first quarter.

That growth is the context for the change. A non-traded BDC scaling toward a billion dollars of assets runs a finance function that touches quarterly valuation, credit facility compliance and subscription processing at once, and allocators tend to treat continuity there as a proxy for operational stability. Filling the role from within the adviser’s own finance leadership, on the same day the outgoing officer left, points to a planned rather than an abrupt transition.

Chief executive and president Timothy Lower signed the report. The next disclosure worth watching is the September quarter, the first to be certified under the new officer.