LONDON (Reuters) - British business leaders from companies including BT (>> BT Group) and Centrica (>> Centrica) said they wanted a three-year Brexit transitional deal to protect jobs in Britain and Europe.

In a letter organized by the Confederation of British Industry (CBI), more than 100 companies employing a total of more than one million people in Britain and the European Union said they needed to make decisions now about investment that will affect jobs in the future.

"Until transitional arrangements can be agreed and trade discussed the risk of 'no deal' remains real and has to be planned for, with inevitable consequences for jobs and growth on both sides," it said.

Brussels has said talks on Britain's future trading relationship with the EU can only start after the other 27 EU governments are satisfied that "sufficient progress" has been made on the terms of the departure. Britain is due to leave the union, deal or no deal, in late March 2019.

Prime Minister Theresa May's office caused dismay within the business community earlier this month when it asked business leaders to put their name to a letter backing the government's approach to Brexit. The letter did not materialize. [nL8N1LN4WY]

"Businesses across the EU and UK are clear: being able to plan for a transition of up to 3 years that avoids a cliff edge is critical for our collective prosperity," the letter organized by the country's leading trade body said.

(Reporting by Kate Holton, editing by Estelle Shirbon)

Stocks treated in this article : BT Group, Centrica