Michael McDonnell. Credit: Intelsat

PARIS — Satellite fleet operator Intelsat on Oct. 19 said its chief financial officer, Michael McDonnell, had tendered his resignation, effective mid-December, and that the company had begun an external search for a successor.

McDonnell oversaw Intelsat’s initial public offering of stock in April 2013 as well as efforts to use the current low-interest-rate environment to lower Intelsat’s still-substantial annual debt payments.

McDonnell, who has been Intelsat’s chief financial officer since 2008, will become chief financial officer at healthcare service provider Quintiles of Research Triangle Park, North Carolina. As of Oct. 19 Quintiles had a market capitalization of $8.8 billion.

Intelsat Chief Executive Stephen Spengler issued a statement thanking McDonnell for his work. “We wish him the best,” Spengler said.

Weighed down by $14.7 billion in debt – mainly the result of successive leveraged buyouts by private-equity firms — and the softness of a couple of its core markets, Intelsat has been struggling with declining revenue as it awaits the launch of its Epic high-throughput satellites.

Intelsat shares, traded on the New York Stock Exchange, have been testing new lows in recent weeks. As of Oct. 19 the company’s market capitalization was just $670 million.

Peter B. de Selding was the Paris bureau chief for SpaceNews.