According to News International, Agar, who had been reported to be leaving the Rupert Murdoch-owned company, has by mutual consent agreed to take on the job on an "acting" basis.
In his caretaker marketing director role at News Group Newspapers, the NI division housing The Sun and the News of the World, Agar will assist in the search for a replacement for Canning. Canning departed in October to take up the post of marketing director at retailer Iceland, owned by the Big Food Group.
A spokesman for News International said: "Andy will continue to work closely with the existing team and Camilla Rhodes [managing director of News Group Newspapers] to ensure that the ongoing development of the marketing strategy of both newspapers."
It is unclear what happens after a replacement for Canning is found in December, whether after that time Agar will return to his role of promotions director for News Group or whether he will, as speculation has suggested, leave the company.
Canning was the second high-profile loss News Group has suffered to its marketing department this year. Prior to Canning's departure, it lost head of marketing Roland Agambar, who left for Richard Desmond's Express Newspapers in March.
Agar has been at News International for four years. He was made promotions director three years ago, having previously been promotions manager. He joined the Rupert Murdoch-owned firm in 1998 from what was then Mirror Group, where he had been trade marketing manager.
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