American Express Global Business Travel has bought a 35% equity share held by Spanish hotel group Barcelo in American Express GBT Spain.
It means GBT Spain is now a wholly-owned subsidiary of American Express GBT.
A spokesman for American Express GBT said the companies had different strategies and had decided to part company.
Luis Dupuy de Lome, general manager GBT Spain, said: "Our joint venture with Barcelo has been a success story since its inception nine years ago. We thank them for their partnership.
"While the joint venture is ending, nothing changes for customers. It is business as usual. This is only a transaction between shareholders. Our staff, brand and value proposition remain the same. Furthermore, we now enjoy the benefit of being wholly owned by American Express GBT."
