The BTA said Lufthansa would play a key role in its campaigns and events this year.
The partnership will also help BTA members forge closer ties with the airline group and further utilise the Lufthansa network.
BTA chief executive Clive Wrattan said Lufthansa’s membership would support the recovery of the business travel sector.
“It is a vital time for airlines as the demand for travel grows in both business and leisure sectors, and we’re delighted to have Lufthansa engaged with us," said Wratten.
Frank Wagner, Lufthansa Group general manager UK, Ireland and Iceland, added: “Rejoining the BTA was the natural next step for us as we look for a smooth recovery process.
"We’re looking forward to benefitting from the BTA’s support and expertise as traffic levels grow again.”
