Saudi Arabia was just handed another reason to list its potentially $2 trillion oil giant in London. 

The regulatory body in the United Kingdom in charge of overseeing its financial markets said it plans to accommodate companies controlled by sovereign nations, in a move that experts have said could influence the kingdom to list its economic crown jewel on the London Stock Exchange.

The Financial Conduct Authority said Thursday, July 13 that it plans to create a distinct category for companies controlled by sovereign countries in its premium listing regime. The structure would enable Aramco to list on the London Stock Exchange while evading some requirements that apply to other companies granted premium status.

Whether Aramco would be allowed to list on London's premium market without floating the required 25% of its shares was said to be a sticking point for Saudi Arabian decision-makers, who are debating an assortment of legal, economic, and political factors as they choose where to list the potentially $2 trillion oil giant. The new plan could reduce that requirement, which would be essential as Aramco has said that it plans to list only 5% of the company on public markets in the latter half of 2018.

"It may not seal the deal, but it brings [a listing in London] closer to a strong possibility," Atlantic Council Global Energy Center senior fellow Jean-Francois Seznec said in an email. "I fully expected the FCA to propose these changes as it is vital to ensure London good continuation as a financial center, especially at a time of Brexit uncertainties," he said.

Critics of the FCA's decision say that it will harm investors in UK markets. Reuters reported last month that leading fund managers in the country were hesitant to embrace changing the rules for Aramco, concerned with potential issues with corporate governance and transparency.

The premium market generally grants companies a lower cost of capital, according to the London Stock Exchange website.

"As Premium Listed companies comply with the UK's highest standards of regulation and corporate governance, as a consequence they may enjoy a lower cost of capital through greater transparency and through building investor confidence," it says.

Besides London, the other major contender for a piece of the listing is New York, generally seen as the favorite among the royal family. A listing on the New York Stock Exchange is seen as a way of shoring up American support as the kingdom faces off with its longtime antagonist in the region Iran. New York is seen as risky, however, as a law passed last year by the U.S. Congress could put Saudi Arabia's American assets at risk by making the country liable for its alleged role in the September 11 attacks.