Elon Musk's tumultuous will-he-or-won't-he $44 billion bid to buy Twitter was dead in the water on Friday, after the Tesla CEO sent a letter to the social media company's board saying he was terminating the acquisition.

Twitter said it will sue Musk to complete the merger and that it is "confident" it will prevail.

Bret Taylor, the chair of Twitter's board, tweeted that the board is "committed to closing the transaction on the price and terms agreed upon with Mr. Musk and plans to pursue legal action to enforce the merger agreement."

Twitter could have accepted the $1 billion termination fee Musk agreed to should he pull out of the deal.

What is the story behind the deal?

The drama between Twitter and the world's richest man was set off in March when Musk announced he would pull the funds together to buy the company he thought was failing to live up to its potential to promote free speech. He also revealed that he had been talking to executives at Twitter, including co-founder Jack Dorsey, to let them know he was buying up shares in an attempt to gain a majority.

However, in the weeks that followed, Musk wavered between doubling down on his determination to buy the company and threatening to walk away from the deal.

In a court filing, Musk's lawyers said that Twitter had breached the acquisition agreement by failing to provide enough information about fake accounts on its platform. According to the document, this was an important piece of data for measuring the company's business performance.

Shares of Twitter fell 6% in extended trading following the news.

es/sms (AP, Reuters)