Formation of inter-project ties from the sender–recipient perspective: Roles of task interdependence and functional interdependence

•This study examines the formation of inter-project ties in different stages from the sender-recipient perspective.•In the design stage, the sender and recipient teams’ task interdependence were negatively related to tie formation.•In the design stage, the sender team's functional interdependence was positively related to tie formation.•In the construction stage, the sender team's task and functional interdependence were negatively and positively related, respectively, to tie formation.•In the handover stage, the formation of inter-project ties is positively related to prior ties in the construction stage.