ISTANBUL/DUBAI: A Getir founder said on Wednesday he would pursue legal action against what he called an "illegal coup" by Mubadala, the Turkish fast-delivery company's largest shareholder, which was moving to secure shareholder approval for its takeover bid.

In a dramatic escalation of a power struggle for Getir, Nazim Salur, one of two founders, said on social media site X that the Abu Dhabi state fund Mubadala was breaching a June restructuring agreement.

Asked about the founders' plans to sue, which was reported earlier by Reuters, Mubadala said that Getir's independent directors had already backed its "alternative transaction" for the grocery delivery company.

Mudabala said it had promoted the alternative plan after the founders "demonstrated an inability" to complete the June agreement for funding and splitting the company in two. It will present its new plan to Getir's shareholders in the coming week, it told Reuters.

In September, Turkey's competition board said Mubadala had applied to take sole control of Getir, though no further details had since been given.

Getir, a pioneer of fast grocery delivery businesses, was once valued at more than $10 billion but has been bruised as consumer demand for deliverables waned.

The company closed down its overseas operations last summer to secure $250 million in funding from Mubadala. In exchange, it would separate noncore businesses from the profitable local grocery delivery operations, which Mubadala would acquire.

The remaining subsidiaries would be placed in a structure controlled by the founders, Salur and Serkan Borancili. A representative for Borancili was not immediately available to comment.

The founders have petitioned to annul Mubadala's call for a shareholders' meeting on Sunday of the Netherlands-based umbrella company Getir BV, where it intends to finalise control of the company, the source said, adding that a decision could come on Friday.

Mudabala said its plan "will secure Getir's financial stability and allow for the execution of its long-term business plan, protecting and sustaining employment for over 18,000 Turkish employees."

"This new agreement was unanimously approved by the Independent members of the Board of Directors," the fund said. "It will now be presented to shareholders for approval at an Extraordinary General Meeting in the coming week." (Reporting by Ebru Tuncay and Can Sezer in Istanbul and Federico Maccioni in Dubai; Writing by Jonathan Spicer; Editing by Alexander Smith and Matthew Lewis)