In 2006 an investment fund acquired Ko Samui airport from Bangkok Airways through a 30 year lease agreement. The money was presumably partly used to finance the expansion of Samui airport . The six new terminals opened in 2007, increasing the annual passenger capacity from 1.3 million to 6 million.
On may 27, 2021, the board of directors Bangkok Airways decided it would like to terminate the lease agreement (576 million USD) as compensation. 30% of the shares in the fund are actually owned by Bangkok Airways itself.
Bangkok Airways remains owner of the airport
Source: Bangkok Airways