Britain's largest local authority concluded a landmark "post-Brexit" trade visit to Qatar on Tuesday in a bid to secure up to $6.5 billion in investment.

Birmingham City Council's three-day business tour to the Gulf is thought to be the first ever undertaken by a British local authority to Qatar to seek funding.

Council leader John Clancy said the visit was in direct response to the British vote to leave the European Union.

"To be frank, it's a post-Brexit thing," said Clancy.

"It's part of a post-Brexit resettlement and cities in the UK in particular have to have an international profile."

Birmingham, with a population of more than one million and located in England's west Midlands, wants billions for infrastructure projects and new homes as it seeks to meet the cost of regenerating two areas in Britain's second most populous city.

The council describes itself as the largest UK local authority.

Clancy was in Doha with a four-strong team, including members of "Marketing Birmingham", a public and privately funded group which seeks to attract investment to the city.

They met Qatari government ministers and business leaders and were supported by British officials and embassy staff.

"We have had strong input from the Department of International Trade, strong embassy support -- that says a lot about government policy."

In the past Birmingham has used European Union funding to help regenerate the city, including money for a convention centre and transport.

But the uncertainty caused by Brexit has caused it to look elsewhere and this week's visit follows a similar trade visit to China by Birmingham council leaders last year.

In recent weeks, two British government ministers -- Philip Hammond and Liam Fox -- have visited Qatar to try to improve flourishing trade links between the two countries, thought to be worth around $6 billion a year.

And at the end of last year, Prime Minister Theresa May visited Bahrain for a two-day Gulf Cooperation Council meeting.

According to official London figures, Britain is the fourth largest exporter to Qatar.

Investments in Britain by the gas-rich Gulf emirate include Harrods, Canary Wharf, a stake in Heathrow and The Shard.

Birmingham will also host a UK-Qatar trade conference in March.