Kirby’s bottom line has flipped back into the black with some help from its shipping business.

The Houston-based tank-barge owner posted a $39m profit for the three months ending on 30 September, a substantial increase from the $265m loss recorded for the same period last year.

The performance was helped by a $95m increase in marine transportation revenue, which hit $433m for the quarter, up from $339m a year earlier.