Elon Musk-led SpaceX Corp is raising US$507 million in a new round of funding, valuing the company at around US$26 billion, according to a filing seen by Reuters.

New articles of incorporation filed by the company last week and sent to Reuters by private analytics firm Lagniappe Labs showed the addition of 3 million 'Series I' shares from a previous version filed in November.

The filing also gave the initial value of the Series I shares as US$169, 25 per cent higher than a value given in its previous fundraising round late last year.

SpaceX declined to comment on the new funding round, which was first reported by tech industry website The Information.

The Hawthorne, California-based company has outlined plans for a trip to Mars in 2022, to be followed by a manned mission to the red planet by 2024.