Stark and Grant were seven strokes behind the winning duo of Gina Kim and Yana Wilson in Midland, Michigan. The Americans went into the final day at -8.
During Sunday's final round, the format of play was best ball - the players choose the best result on each hole - but it took until the ninth hole before the Swedes recorded a birdie.
The Swedes also birdied holes 11 and 12, but otherwise recorded only pars, and with three strokes under par for the day it was difficult to challenge for the victory.
Dani Holmqvist and Madelene Sagström shot a 64 (six under par) in the final round, and with a combined -10 they share ninth place with their compatriots.
