Guardian Media Group has announced that its chief executive, Annette Thomas, has decided to leave the company at the end of June. Thomas joined the parent company of the Guardian and Observer as chief executive in March last year. In April 2021, the Scott Trust, the sole shareholder in GMG, began a review of the trust and GMG’s governance and structures, a process that GMG said Thomas had supported and to which she contributed. Keith Underwood, the chief financial and operating officer, will lead GMG on an interim basis as acting chief executive. The GMG chair, Neil Berkett, said: “On behalf of the GMG board I would like to thank Annette for the vital role she has played. In a year of lockdown, Annette has renewed and enhanced our strategy in conjunction with the editor-in-chief, a process the board has fully supported. “The GMG board is immensely grateful to Annette for her significant achievements and for her consistent commitment to her principles and to the company’s values. We are disappointed she has chosen to leave, but we wish her well for the future. “We have a clear strategy and a strong management team in place. Despite the difficulties caused by coronavirus, Guardian and Observer journalism has never been stronger or more relevant and our long-term commitment to trusted reader relationships is beginning to power our growth. “The board will continue to support Keith Underwood, Katharine Viner and the wider management team to achieve our long-term goals.” Thomas said: “I am grateful to the Guardian and the GMG board, and wish the organisation every success in the future with its vital mission.”