El Aynaoui, who also defeated Spain's Albert Portas in the quarterfinals, advanced to his fifth ATP final of the year.
A semifinalist here a year ago, El Aynaoui won the Doha hardcourt and Casablanca and Munich claycourt events. The 30-year-old's lone finals defeat in 2002 came at the Dubai hardcourt tournament.
Robredo registered his third semifinal appearance in his last five outings.
Moya, who advanced to the final in his debut at Bastad, is seeking his second claycourt title this year. He won the Mexican Open in February and is seeking his ninth career title.
Calleri was unable to advance to his second career ATP final. In February, the 25-year-old reached the Buenos Aires claycourt final, where he lost to Chilean Nicolas Massu.
El Aynaoui will meet Moya for the second time in an ATP event. Moya rallied to beat El Aynaoui in their round-of-32 matchup at the 2000 Toulouse hardcourt event.