FRANKFURT, March 24 (Reuters) - Aspex, a top Delivery Hero DHER.DE shareholder, on Tuesday urged the online takeaway food group's supervisory board to oust the CEO and his top management team in an escalation of the investor's campaign for a change in strategic direction.

"Wholesale changes in the management team will be required to address issues faced by the company," Aspex Management said in a letter addressed to Delivery Hero Chair Kristin Skogen Lund and other members of the non-executive supervisory board, which was seen by Reuters.

"Fellow shareholders share our view that $(CEO)$ Niklas Oestberg’s strategy is flawed, and that Delivery Hero’s operational underperformance against peers is accelerating," the letter said, adding that the company was to be heavily burdened by compliance and control failure.

Delivery Hero said it acknowledges the latest letter from Aspex.

"We are progressing with the strategic review and it remains an ongoing core focus of both the Management and Supervisory Board," the company said in a statement in response to the letter.

(Reporting by Alexander Huebner in Munich and Hakan Ersen in FrankfurtWriting by Ludwig BurgerEditing by Madeline Chambers)