WARRENPOINT, Northern Ireland – The director of ports in Maine’s largest city would like to boost traffic in Portland Harbor by diverting Guinness stout and Bushmills whiskey from South Carolina.

Jeff Monroe and other Maine transportation officials also are looking for insight into how they can make trade more cost-effective and profitable for businesses on both sides of the Atlantic.

One strategy Monroe has been pursuing on Gov. John Baldacci’s trade mission to Northern Ireland is to shift the spigot of alcoholic beverages north from its current flow to Charleston, S.C.

The historic concern has been that drinks freeze while sitting on northern docks for several winter days, waiting for truck delivery. But Monroe thinks he could overcome that problem with a temperature-controlled, 75,000-square-foot building to house the beverages until they head to customers across the Northeast.

“We’re big consumers,” Monroe told Warrenpoint port officials in a meeting Wednesday. “We’re trying to tap into that market.”

Part of the reason for seeking new customers is that freight volume through Portland has dropped dramatically in the last two years, following the closure of three major paper mills. The loss of that business has caused exports at the port to fall from 65 percent of its volume in 2001 to a projected 35 percent this year.

So, Monroe is looking for new business to help support the Port of Portland and the jobs it sustains. The key is to find trading partners with whom to swap shiploads of merchandise, and Monroe spent Tuesday with port officials from Londonderry and Wednesday with managers from Belfast and Warrenpoint, making his case.

Warrenpoint, which is located at the southeast tip of Northern Ireland, handles about 2 million tons of cargo a year.

In comparison, Portland handles about 750,000 tons of bulk products a year, in addition to 30 million tons of oil products.

The problem right now for Maine is that little at Warrenpoint is outbound. After the demise of Delorean cars, Northern Ireland’s economy has focused more on services such as legal work and does little manufacturing for export.

That leaves the well-respected Bushmills single-malt whiskey dominating the export market.