Rugby World Cup-winning South Africa captain Siya Kolisi has officially signed with the Sharks.

Kolisi was at the weekend released from his contract with the Stormers, which had been due to expire in October, upon the acceptance of a transfer fee.

The 29-year-old flanker was expected to join Durban-based franchise the Sharks and that move was confirmed on Wednesday.

Kolisi made 118 Super Rugby appearances in his 11 years with the Stormers, for whom only Schalk Burger (123) managed more.