Rona Fairhead has said she would “keep under review” her ability to combine her job as BBC Trust chair with the role of non-executive director of HSBC, insisting the broadcaster was her main focus.

Fairhead has been a non-executive director of HSBC since 2004 and was chair of its audit committee at the time covered by the HSBC files. She was paid £513,000 by the banking giant last year.

Fairhead, who also serves on the board of Pepsi, told the Oxford Media Convention on Wednesday: “I was very clear, it was on public record when I took this role, that the BBC would be my main focus of attention and I would keep under review my ability to sit on the boards of HSBC and Pepsi and that continues to be my position.

“I have made a public commitment to make the BBC my focus and I am very committed to making that work.”

Fairhead, who is paid £110,000 a year for her three-days-a-week trust role, confirmed she would appear before the Commons public accounts select committee next week.

“I’m here in my role as the BBC Trust chair,” she said. “I am appearing in front of the public accounts committee on Monday and I look forward to doing that. That is the right place to talk about HSBC.”

The HSBC files – obtained through an international collaboration of news outlets including the Guardian, the French daily Le Monde and BBC1’s Panorama – revealed last month that its Swiss banking arm had helped wealthy customers dodge taxes and conceal millions of dollars of assets, doling out bundles of untraceable cash and advising clients on how to circumvent domestic tax authorities.