Complex sentence: Finnish Commuter Airlines Oy, trading as Finncomm Airlines, is a regional airline headquartered at Seinäjoki Airport in Seinäjoki, Finland, with a main base and hub at Helsinki-Vantaa Airport.
Split into simpler sentences: Finnish Commuter Airlines Oy, trading as Finncomm Airlines, is a regional airline based in Seinäjoki, Finland. The headquarters is located at Seinäjoki Airport but with a main base and hub at Helsinki-Vantaa Airport.