Elon Musk says he has lined up $46.5 billion in financing to buy Twitter, and he’s trying to negotiate an agreement with the company. Last week, Musk announced an offer to buy the social media company for $54.20 per share, or about $43 billion. At the time, he did not say how he would finance the acquisition. The Tesla CEO said Thursday in documents filed with U.S. securities regulators that he’s exploring what’s known as a tender offer to buy all of the social media platform’s common stock for $54.20 per share in cash. Under a tender offer, Musk, who owns about 9% of Twitter shares, would take his offer directly to other shareholders, bypassing the board. But Musk hasn’t decided yet whether to do that. The documents filed with the Securities and Exchange Commission say San Francisco-based Twitter Inc. has not responded to Musk’s proposal. Last week Twitter’s board adopted a “poison pill” defense that could make a takeover attempt prohibitively expensive. Read: Elon Musk wants to buy Twitter, make it 'maximally trusted' The filing states that “entities related to (Musk) have received commitment letters committing to provide an aggregate of approximately $46.5 billion.” The financing would come from Morgan Stanley and other financial institutions. Some would be secured by stock that Musk owns in Tesla, the electric car and solar panel maker. Other banks involved include Barclays, Bank of America, Societie Generale, Mizuho Bank, BNP Paribas and MUFG. Shares of Twitter were down slightly to $46.69 in Thursday morning trading after the financing became public. The share price is $7.51 below Musk’s offer. Musk “is seeking to negotiate a definitive agreement for the acquisition of Twitter ... and is prepared to begin such negotiations immediately,” the documents say. With a tender offer, Musk would try to get other shareholders to pledge their stock to him at a certain price on a certain date. If enough shareholders agree, Musk could use that as leverage to get the board to drop the poison pill defense. Musk signaled the possibility of a tender offer several times this week in tweets using the word “tender.” A message was left Thursday seeking comment from Twitter.