Mainers – and Harold Alfond’s heirs – apparently benefited mightily from the “worst deal” billionaire financier Warren Buffett ever made.

In his annual letter to Berkshire Hathaway shareholders, issued to investors Feb. 29, Buffett lamented that he “gave away 1.6 percent of a wonderful business” when he bought the Maine-based Dexter Shoe Co.

Known as the “Oracle of Omaha,” Buffett purchased Dexter for $433 million in stock from owners Harold Alfond and Peter Lunder in 1993.

That purchase became the basis of the Alfond Foundation which, over the years, funded sports facilities and other charitable ventures around the state. Last year, upon Alfond’s death, the fund established a pilot program which eventually will provide a $500 college savings account for every child born in Maine, at an estimated annual cost of $7 million to the fund.

If parents contribute $50 per month from that point on, each Maine child could have $25,000 saved by the time he or she reaches college age.

According to Buffett, however, Maine’s gain has been his fund’s loss. “Dexter is the worst deal I’ve made,” he told investors.

Dexter, Buffett figured in 1993, had a competitive advantage in the shoe market: Its made-in-U.S. reputation. So he bought the Maine-based company.

“What I assessed as a durable competitive advantage vanished within a few years,” Buffett wrote in his 2007 message.

“But that’s just the beginning,” he wrote. “By using Berkshire stock, I compounded this error hugely. That move made the cost to Berkshire shareholders not $400 million, but rather $3.5 billion. In essence, I gave away 1.6 percent of a wonderful business…to buy a worthless business.”

The deal made Alfond the largest Berkshire stockholder, except for Buffett and his family. But, once in Buffett’s hands, Dexter struggled to make a profit.

Meanwhile, as the value of Berkshire Hathaway grew, Alfond’s fortune multiplied many times over.

Alfond died last year at 93. His legacy, however, includes more than a dozen sports facilities around the state, the College Challenge Fund, as well as the $7 million Harold Alfond Center for Cancer Care in Sidney, which opened last July.