The commitments come as the Tesla billionaire marshals capital to bankroll one of the biggest tech industry takeovers.
The investors named in the filing on Thursday include crypto exchange Binance, Brookfield, Fidelity Management & Research, and Qatar Holding.
Musk has also won the support of fellow entrepreneur and Oracle co-founder Larry Ellison, who has a big stake in Tesla and a seat on its board. Ellison’s trust has committed $1 billion to finance Musk’s takeover.
Twitter shares rose 2.5% in pre-market trading.
The world’s wealthiest person reached an agreement on April 25 to acquire Twitter using a financing plan that’s alarmed some Tesla investors.
In addition to pledging tens of billions of dollars worth of his Tesla shares to support margin loans, Musk vowed to line up some $21 billion worth of equity. It’s been unclear how much of that would come from selling a portion of his Tesla stake.
Saudi Prince Alwaleed bin Talal, chairman of the board at Kingdom Holding Company and one of Twitter’s largest backers, has now agreed to roll over his current investment.
He previously rejected Musk’s bid, stating that it failed to come “close to the intrinsic value of Twitter.”
Musk is also in discussions with Twitter co-founder Jack Dorsey on contributing some of his shares toward the acquisition. A previously announced margin loan committed toward the deal was reduced to an aggregate principal amount of $6.25 billion from $12.5 billion.