(Reuters) -- Billionaire Elon Musk is proposing to go ahead with his original offer of $54.20 per share to take Twitter private, two sources familiar with the matter said on Tuesday, sending shares of the social media firm surging.

Twitter shares jumped 12.7% to $47.93 before trading was halted for the second time, while Tesla, the electric-vehicle company that Musk heads, rose by 1.5%.