The chairman and chief executive of Bank of America says major companies like his need clear rules before deciding how much business to maintain in Britain after it quits the European Union.

Brian Moynihan and other top bankers and executives gathered at the World Economic Forum in Davos are eagerly awaiting details about the UK exit plans from British Prime Minister Theresa May in a speech Tuesday.

Moynihan, speaking to The Associated Press, said Bank of America is working on “all kinds of scenarios” to possibly shift activities out of London after Brexit, but insisted “it's still not clear what that would do, or wouldn't do.”

He said: “It's still premature to say what anybody's going to do until you have one set of rules. London will be an important part of our company no matter what happens with the British economy.”