LONDON (Reuters) - The United Kingdom lost market share in the United States, Germany and China during the COVID-19 pandemic due to global trade chaos, Brexit and poor productivity, according to new research published on Monday. The United Kingdom performed particularly badly due to a long-term stagnation in productivity growth, according to the report by Aston University’s Lloyd’s Banking Group Centre for Business Prosperity. While all countries grappled with the tumult of COVID-19, the United Kingdom lost market share in its biggest export markets - the United States and Germany, the research showed. “In some key export destinations – Germany, the UK and China - the UK seems to have suffered a sharper decline, experienced a slower recovery, and seen its global competitiveness dwindle,” the report said. “The UK’s decline in exports to the U.S. appeared the sharpest in both absolute and relative terms and the most prolonged among the major European countries (except for France).” Between 2017 and 2019, the UK increased total exports to Germany by 8.5% - less than the export growth achieved by Italy(12%), the Netherlands (14%) and Spain (20%), as well as the United States (24%). “This to some extent paints a picture of slowing UK exports to Germany following the 2016 Brexit referendum, which may indicate some decoupling between the two economies,” economists Jun Du and Oleksandr Shepotylo said in the report. The research, based on United Nations trade statistics, also indicates that the UK lost market share in China. here “The combination of COVID, Brexit and the UK’s long-term productivity challenges will put British businesses in an adverse position for the foreseeable future,” the report said. The United Kingdom’s relatively poor productivity has puzzled economies for years: explanations vary from a poor employee skills and low research investment to demand-side factors such as the financial crisis. ($1 = 0.7225 pounds)