There will be a lot of congestion around the Long Island Expressway in Melville this morning, but not the usual car kind.

Business people, politicians and civic officials will be on hand at about 10:30 a.m. for a groundbreaking that will kick off one of the largest construction programs on the Island in years: the building of a North American headquarters for imaging company Canon Inc.

Gov. David A. Paterson, Sen. Charles Schumer (D-N.Y.), Huntington Supervisor Frank Petrone, other members of Congress and the State Legislature, and Canon executives are expected to be on hand.

Canon, currently in Lake Success, is building a $636-million, 668,296-square-foot building at the southwest corner of the LIE South Service Road and Walt Whitman Road in Melville.

The company, with 1,000 employees here now, is expected eventually to have 2,000 employees at the new building.