The ttrade deal with Cuba was with a state-run food agency Alimport.
Under the deal, Alimport will buy Maine products worth $20m (kr. 140 mill) by July 2007, including seed potatoes, fish and dairy cattle.
Mr Baldacci is due to meet Cuban President Fidel Castro later on Monday.
In 2001, Maine was the first US state to pass a resolution calling for a complete end to the trade and travel ban against the Caribbean nation.
Mr Baldacci said that, during his trip, he hoped to see his country’s relations with Cuba normalised step-by-step.