Lucy Frazer said she is concerned about the potential influence of Abu Dhabi over The Telegraph.
The move was prompted by Redbird IMI making changes to the corporate structure of the potential acquiring entities of TMG.
The Delaware limited liability corporation Redbird IMI Media Joint Venture LLC was the sole shareholder of RB Investco Ltd, the company with the right to buy The Telegraph.
But on Tuesday the structure was changed so a new English limited partnership, RB IMI AIV Limited Partnership, with RB Investco Limited as a subsidiary, now holds all the shares.
International Media Investments (IMI), which is privately owned by UAE vice president Sheikh Mansour, remains the majority stakeholder in both.
Read more: pressgazette.co.uk