Former Shell chief Ben van Beurden has fueled fears that the company could swap London for New York.
Van Beurden, who was chief executive until 2022, told the FT Commodities Glodal Summit that the gap between stock market valuations for European and American oil companies is a "major issue".
He added that the US has a "more positive" attitude towards traditional energy companies, which makes switching to the New York Stock Exchange an attractive proposition for some.
The former energy giant's leader also admitted that considerations were made in 2021 about a switch to New York, but leaving Europe was viewed as a "bridge too far".
The company dropped it dual listing and moved its headquarters to London.
"Of course we looked at all sorts of options," van Beurden said.
"We thought that going to the UK was the most logical next step. Was it going to be the end game? You always have to reconsider what other options are there."
Van Beurden's warnings follow current chief Wael Sawan saying he's looking at "all options", leaving to door open of a potential switch.
Should Shell wish to move their primary listing away from London, they would require 75% approval in a shareholder vote.