Syrian tycoon Rami Makhlouf issued a video statement on Sunday saying officials had told him to quit as head of mobile operator Syriatel, in the latest twist in a tussle over assets and taxes that has uncovered a rift at the heart of Syria's ruling elite.

Makhlouf, a cousin of Bashar Assad, said he would resist the pressure and refuse to step down as chairman – even though he said the officials had threatened to revoke the firm's license and seize its assets if he did not comply.

There was no immediate comment from the regime.

Makhlouf, once widely considered part of Assad’s inner circle, has a business empire that ranges from telecoms and real estate to construction and oil trading.

He played a big role in financing Assad's war effort, Western officials have said, and is under U.S. and European Union sanctions.

But the video message – the third he has issued on the dispute in less than a month – underlined divisions that Syria experts say could mark the first major rift within the dominant Alawite sect since Assad's uncle Rifaat tried to depose Assad's father, the late President Hafez Assad, in 1984.

In the statement issued on Facebook, Makhlouf said officials that he did not name had told him: "If you don't comply ... the license will be revoked."

"They said you have until Sunday to either comply or the company will be taken and its assets seized," Makhlouf said, adding they were threatening board members with arrests. It was not immediately clear when the video was recorded and which Sunday he was referring to.

He said there would be a "catastrophic" blow to the economy if Syriatel collapsed. The company is one of the war-ravaged economy's main sources of revenue – Makhlouf has said it has 11 million subscribers.

On April 30, he issued a statement saying he would appeal to Assad to allow Syriatel to reschedule payment of taxes owed to the regime to avoid the collapse of the firm.

On May 3, he said security forces were arresting employees at his companies "in an inhumane way" amid pressure on him to step down from his business empire and pay millions of dollars in taxes.

In Sunday's message he attacked unnamed profiteers that he said had moved in during the war. "Those who had been before the war are concerned about the country and sacrificed everything," Makhlouf said.

The billionaire has been under U.S. sanctions since 2008 for what Washington calls public corruption, and it has since toughened measures against top businessmen who are close to him.

The EU has also slapped sanctions on Makhlouf since the Syrian conflict began in 2011, accusing him of bankrolling Assad.