City representatives were 'proud' to visit Bangladesh last week and form a permanent bond with Sylhet - where many of Portsmouth's 10,000-strong Bangladeshi community have roots.
As part of a twinning trip members of Portsmouth City Council, the Portsmouth Bangladesh Business Association (PBBA), the University of Portsmouth, the port and other groups arrived in Bangladesh on November 16.
Portsmouth City Council leader, Councillor Gerald Vernon-Jackson, said: 'This has long been my ambition and the newly formed PBBA has given us the perfect way to make the twinning of our two great cities really meaningful.
'The firms who have joined us on this trip have found it very beneficial and we all hope it will help grow jobs and opportunities for business at home and here in Bangladesh.
'We must now work more closely to grow our links even further.'
On arrival in Dhaka the delegation met the head of trade at the British High Commission and board members of the Federation of Chambers of Commerce in Bangladesh.
They then travelled to Sylhet where the Mayor of Sylhet, Ariful Haque Choudhury, and Cllr Gerald Vernon-Jackson signed the sister city agreement.
Cabinet member of the Bangladeshi government, the Honorable Minister Md. Mahbub Ali, said: 'There are already strong links between our two great cities but this formal sister city agreement will make those links even stronger and help generate economic growth for both Portsmouth and Sylhet.
'I welcome everyone to visit Bangladesh and experience our culture.'
It is hoped the bond will lead to both trade and educational links between the cities. The University of Portsmouth is looking to attract students from Bangladesh to the city as well as begin an academic partnership, and already has a representative based in Sylhet.
Chairman of the PBBA, Raja Ali, said: 'This will further enhance the relationship between the cities and bring tremendous economic benefits from the memorandum of understandings signed with numerous chambers of commerce and business associations.'
The Bangladeshi community in Portsmouth is the city's largest non-British white group.