The shell company seeking to merge with former President Donald J. Trump’s social media company announced late Wednesday that it had postponed a crucial meeting of shareholders scheduled for Thursday, at which it hoped to announce that investors had agreed to give it more time to complete its long-delayed deal.

The company is now giving shareholders until Sept. 5 to approve the measure to give it more time to complete the deal with Trump Media & Technology Group. That is just three days before the shell company, Digital World Acquisition Corp., would be forced to begin to liquidate and return the $300 million it raised from investors in a September 2021 initial public offering.

Digital World was set up as a special purpose acquisition vehicle, or SPAC, which raises money by going public to finance a future merger — in this case, Trump Media. The merger was announced on Oct. 21, 2021, and Digital World now is trying to get 65 percent of its roughly 400,000 shareholders to approve the extension for the deal.

The vote to delay the liquidation date comes after Digital World reached a settlement with the Securities and Exchange Commission on July 20 to resolve an investigation into events preceding the original merger announcement. Digital World’s settlement requires it to pay a penalty of $18 million once the merger is completed and revise some of its filings to comply with federal securities laws.

A year ago, when Digital World was faced with a similar need to delay the liquidation date, it took several postponements to get enough shareholders to approve the move. But the company is in a time crunch this year, because it cannot delay the vote on the extension beyond the Sept. 8 liquidation date.

SPACs are required by securities laws to return cash raised in a public offering to investors if they are unable to complete a merger in specified period. To date, roughly 30 percent of the 947 SPACs that went public since the beginning of 2020 have had to liquidate, according to SPACInsider, a research firm.

If the Digital World merger is completed, it will provide Trump Media, the parent company of Truth Social, with a badly needed cash infusion.

Earlier this month, Trump Media recommitted itself to completing the deal by year’s end but only after it got new terms that would strengthen Mr. Trump’s control over a merged company.

Under a revised agreement, Digital World would issue a new class of shares that will give Mr. Trump at least 55 percent voting power over all shareholder measures. Mr. Trump will also own a majority of the company’s main common stock after the merger, according to regulatory filings.

At its peak, Digital World’s stock traded at around $97 a share, but the delay sapped much of that early investor euphoria. Still, at $17 a share, it is trading significantly above its roughly $10 a share liquidation value.

Truth Social has emerged as Mr. Trump’s primary megaphone for railing against his political opponents and the federal and state prosecutors who have brought four indictments against him.

But the social media platform’s growth has slowed after its official introduction last year. This year, the Truth Social app has been downloaded two million times, according to the data analysis firm Sensor Tower. In total, Truth Social has been downloaded six million times since it was introduced.