San Francisco, California - Elon Musk has unveiled the next step of his Twitter rampage by using his deep pockets in a bid to buy all the company's outstanding shares.

Musk tweeted about his letter to Twitter, which contained a non-binding proposal to acquire buy the remaining common stock not owned by him for cold, hard cash at $54.20 per share. That massive bid would cost Musk an estimated $41 billion, according to Reuters.

If Twitter takes him up on the offer, its common stock would be delisted from the New York Stock Exchange.

According to the letter, filed with the Securities and Exchange Commission, Musk worked with the investing services of Morgan Stanley as his financial advisor.

"Twitter needs to be transformed as a private company. As a result, I am offering to buy 100% of Twitter for $54.20 per share in cash, a 54% premium over the day before I began investing in Twitter and a 38% premium over the day before my investment was publicly announced. My offer is my best and final offer and if it is not accepted, I would need to reconsider my position as a shareholder," Musk said.

The proposal is non-binding and, once agreed upon, would be conditioned upon a mountain of any required governmental approvals.

That means due diligence that covers legal, business, regulatory, accounting and tax matters, and hammering out the exact deal agreements with Twitter, as well as making sure Musk would be able to pay up.

Shares of Twitter Inc were up 11% in pre-market trade on Thursday.