(Reuters) -Elon Musk and X Corp have reached a settlement in a lawsuit by four former top executives at Twitter, including former CEO Parag Agrawal, who claim they were not paid $128 million in promised severance pay after Musk acquired the social media company and fired them.

The terms of the settlement, which was first announced in a filing in San Francisco federal court last week, were not disclosed. A federal judge on October 1 pushed back filing deadlines and a hearing in the case so the settlement can be finalized. 

X in August agreed to settle a separate lawsuit by rank-and-file Twitter employees who lost their jobs during mass layoffs and claimed they were owed $500 million in unpaid severance. 

The cases are among a series of legal challenges that Musk, the world's richest person, has faced after he acquired Twitter for $44 billion in 2022, cut more than half of its workforce and renamed it X.

X and lawyers for the former Twitter executives did not immediately respond to requests for comment. The plaintiffs are Agrawal; Ned Segal, Twitter's former chief financial officer; Vijaya Gadde, its former chief legal officer; and Sean Edgett, its former general counsel.

The former executives say that Musk falsely accused them of misconduct and forced them out of Twitter after they sued him for attempting to renege on his offer to purchase the company.

Musk then denied the executives severance pay they had been promised for years before he acquired Twitter, according to the lawsuit. The plaintiffs say they each are owed one year's salary and hundreds of thousands of dollars' worth of stock options.

Musk and X have denied wrongdoing and said the executives were fired over their performance.