It's the world's biggest ever stock market flotation and the London Stock Exchange is desperate to grab a slice of it.

Saudi Aramco, the desert kingdom's state-owned oil company, is preparing to sell shares in itself to outside investors as the country's rulers seek to raise money to plug a gap in their public finances.

The flotation could see Saudi Aramco valued at more than $1tn and so stock exchanges everywhere have been fighting it out to attract what would undeniably be a prestigious listing.

The main listing will be on the Riyadh Stock Exchange, known as the Tadawul, but the Saudis are also seeking a secondary listing for the shares.

New York, London, Tokyo, Hong Kong and Singapore are all keen to get the business.

To that end, during Theresa May's recent visit to Saudi Arabia, the Prime Minister is understood to have made the case for Saudi Aramco to list in London.

She was accompanied on her trip by Xavier Rolet, chief executive of the LSE, who also made a pitch for the business.

In the post-Brexit world, a listing of Saudi Aramco in London would be a powerful signal, sending out the message that the UK remains open for business to the rest of the world.

The flotation would also be a jamboree for the City's lawyers, bankers and public relations advisers.