The purchase could help Fosun promote holiday packages at Club Med as it looks to turn around the firm's struggling business in Europe and move more aggressively into fast-growing markets such as China.
"The investment in Thomas Cook complements other recent investments of the group in the sector, providing opportunities for further value creation," Fosun chairman Guo Guangchang said in the filing. He said there was "increasing demand for international leisure travel".
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The purchase, in the form of a new share issuance at 125.59 pence a share, is being done by Fosun's subsidiary Companhia de Seguros. The price represents a 4.1 percent premium to Thomas Cook's closing price on Thursday.
Thomas Cook is in the middle of a cost-saving plan, but aims to grow this year despite facing tough trading conditions in mainland Europe. It made a loss of around $80 million in the three months to Dec. 31 last year.
Fosun's bid for Club Med which valued the firm at around $1.15 billion, was finalized in early February.