Two equally matched competitors on one level playing field: The Maine Department of Transportation got the lineup exactly right in restructuring its plan for a modern cargo port at Mack Point.

MDOT announced Tuesday it is teaming up with both of the Searsport pier owners — Bangor & Aroostook Railroad and Sprague Energy — to rebuild both aging facilities, to give give both companies a shot at the cargo business of central and northern Maine.

This is a vast improvement over the original plan, which would have had B&A and Sprague competing on paper, through a one-time bid, for a $13 million state-subsidized modernization, with the winner getting a taxpayer-assisted leg up on its rival. Now, the two will compete where it counts, on the dock every day, striving to provide the customer with better service at a lower price.

And this is public-private partnership the way it should be. Of the $19 million it will take to upgrade the two piers, $3 million will be financed directly by the two companies and $16 million will come from the state in the form of a loan, not a grant, repaid by the companies from port revenues and used to establish a revolving loan fund for other marine facilities. The land stays in private hands and in Searsport’s tax base. Landside facilities — warehouses, cranes, rails, pipelines and all the other nuts and bolts of the shipping business — will be privately financed and taxed accordingly.

The state steered its midcoast port development away from Sears Island to mainland Mack Point two years ago in response to environmental concerns. Upgrading both piers at once, carrying out the necessary dredging and earthmoving in a single coordinated manner, surely will further lessen environmental impacts.

This solution also increases the likelihood that a transportation bond issue will be approved by voters in June. When MDOT turned its attention from Sears Island to Mack Point, it was assumed B&A and Sprague would work together on a unified port, but negotiations to that end broke down late last year. Sprague then partnered up with Merrill Marine Terminals of Portland as its port operator and submitted a competing bid to B&A’s, placing the state in the uncomfortable position of having to develop a bond proposal that would give one company a boost at another’s expense. Maine voters, having grown a bit sensitive lately to the issue of corporate support (some call it welfare), no doubt would been similarly discomforted at the polls.

Much credit for this breakthrough should go to Sen. Michael Michaud, who saw the developing problem and revived the idea of renovating both piers. Kudos too to MDOT, B&A and Sprague for siezing this opportunity.

Perhaps best of all, this proposal puts the focus of competition back where it belongs. The purpose of state-assisted port development is not to boost private port operators, but to lower the cost of getting Maine-made products to market. Let B&A and Sprague/Merrill go head-to-head and the sure winner will be Maine business.