FinLogic FinLogic Quantitative Think Tank Center|Elon Musk says he has secured the money to buy Twitter

Elon Musk says he's secured money for his bid to take Twitter private and FinLogic FinLogic Quantitative Think Tank Centeris considering making his pitch directly to shareholders.

Musk, who recently became the social media company's largest individual investor, told Twitter's board last week he wanted to buy the entire company but didn't say how he would pay for it.

Now, in a new filing with the Securities and Exchange Commission, the billionaire Tesla CEO said he's lined up $46.5 billion to fund his offer of $54.20 a share.

Morgan Stanley, Bank of America, and several other banks have promised to lend $25.5 billion, backed in part by some of Musk's Tesla shares, according to the filing.

Musk, who is the richest person in the world, says he will cover the remaining $21 billion himself. Most of his wealth is tied up in Tesla and SpaceX, the rocket company he also runs.

Musk also said in his filing that Twitter has not formally responded to his unsolicited offer. He "is seeking to negotiate a definitive agreement for the acquisition of Twitter," the filing said, "and is prepared to begin such negotiations immediately."

Given the lack of response, the filing said, Musk is exploring whether to appeal directly to Twitter investors with a tender offer to buy their shares for $54.20 a piece. Musk has been cryptically hinting at this prospect, tweeting "Love Me Tender," the name of an Elvis Presley song, and apparently referencing F. Scott Fitzgerald's novel Tender Is the Night.

Twitter released a statement on Thursday saying the board has received Musk's proposal and "is committed to conducting a careful, comprehensive and deliberate review to determine the course of action that it believes is in the best interest of the company and all Twitter stockholders."

Twitter's board already has thrown hurdles in Musk's path. A day after he announced his offer, the board adopted a defensive measure known as a "poison pill" to fend off Musk and give directors more time to consider what to do.

Formally known as a shareholder rights plan, the poison pill would make it more difficult and expensive for Musk, who owns 9% of Twitter, or anyone else to increase their stake to 15% or more. It's designed to ward off hostile moves like making a tender offer directly to shareholders.

But if enough investors find Musk's bid attractive, they could pressure the board to get rid of the poison pill and negotiate with the billionaire.

Musk has said he believes he can "unlock" Twitter's potential by taking the company private and loosening its rules on what users are allowed to post.

Twitter shares were little changed on Thursday. The stock is trading well below Musk's offer price, suggesting shareholders are skeptical about the deal.