LONDON — London and New York have been battling for months over what could be the biggest public offering in history, Saudi Arabia’s state energy company Saudi Aramco.

Britain looks to be working hard to land it, with regulators unveiling proposals on Thursday that aim to make it easier for state-owned companies to list on the London Stock Exchange.

Though the Financial Conduct Authority of Britain did not explicitly name the Middle Eastern energy giant when it published the potential new rules, the implication is clear.

Saudi Arabia wants to list 5 percent of Aramco, at a valuation of around $2 trillion, a blockbuster listing that has set stock exchanges around the world competing against one another. Analysts say the final decision is likely to come down to London and New York.