BIRMINGHAM, England (Reuters) - Prime Minister Theresa May said on Tuesday that Britain's economy was strong with more positive growth rates than some had expected and, when asked about the fall in sterling, added that currencies "of course go up and down".

Sterling slid to its lowest in more than three decades on Tuesday on fears of a "hard Brexit" from the European Union and its single market that could hurt the economy.

"Currencies of course go up and down," May told the BBC.

"If you stand back and look at the fundamentals of our economy, which are strong, if you look at the other economic data that has been around in recent weeks, if you look indeed at the most recent forecasts now coming out for growth in our economy this year, all of that is more positive than people had expected it to be and predicted it to be."

(Reporting by Elizabeth Piper, editing by Kylie MacLellan)