Complex sentence: New York route suffered the greatest loss, so in June 1931 the company suspended the service and sold the ships to Lithgows at Port Glasgow in Scotland, and in August 1932 both ships returned to Scotland.
Split into simpler sentences: New York route suffered the greatest loss, so in June 1931 the company suspended the service and sold the ships to Lithgows at Port Glasgow in Scotland. CSAV continued to lose money, and in August 1932 both ships returned to Scotland.