The Carlyle Group reported in a Securities & Exchange Commission document that the private equity firm, which plans to go public soon, reimbursed co-founder David M. Rubenstein approximately $4.75 million in 2010 for using his personal aircraft to carry out company business. Rubenstein traveled 180 days that year, visiting 24 countries and 33 non-U.S. cities, many more than once.

Rubenstein’s reimbursements for 2009 amounted to $4.05 million. His co-founders, William E. Conway Jr. and Daniel A. D’Aniello, had far less reimbursements for both years.

“As the co-founder primarily responsible for, among other things, maintaining strong relationships with and securing future commitments from Carlyle’s investors, particularly outside the United States, Mr. Rubenstein has an exceptionally rigorous travel schedule,” Carlyle said in the SEC documents.