AUGUSTA – Verizon has completed work on a major infrastructure expansion that extends broadband Internet service to more than 30,000 customers in unserved or underserved portions of the state.

The Public Utilities Commission said the work represents Verizon’s fulfillment of a plan approved by regulators last summer. Under the agreement, Verizon is barred from passing the costs of the project on to FairPoint Communications as part of its takeover of Verizon land lines in Maine.

The new high-speed digital subscriber line, or DSL, service is spread across dozens of large and small communities in Maine. They are:

Acton, Arundel, Auburn, Bangor, Bar Harbor, Belgrade, Biddeford, Boothbay Harbor, Bowdoinham, Brewer, Brooklin, Brooksville, Brunswick, Clifton, Codyville Plantation, Columbia, Cranberry Island, Danforth, Dark Harbor, Dedham, Detroit, Durham, Eddington, Fairfield, Falmouth, Farmington, Franklin, Freeport, Frenchville, Georgetown, Glenburn, Greene, Gouldsboro, Hiram, Houlton, Jefferson, Kennebunk, Lebanon, Lewiston, Limerick, Lubec, Mexico, Monhegan Island, Monroe, Monson, Mount Desert, North Haven, North Sanford, North Whitefield, North Yarmouth, Norway, Ogunquit, Orono, Paris, Pembroke, Phippsburg, Porter, Portland, Pownal, Saco, St. Agatha, Scarborough, Sedgwick, Shapleigh, Somesville, South Portland, Southport Island, Sullivan, The Forks, Topsfield, Topsham, Tremont, Vanceboro, Wayne, Wells, Westbrook, Westport, Whitefield, Windsor, Woolwich and Yarmouth.

The expansion increases to 70 percent the proportion of Verizon land-line customers in Maine with high-speed Internet access.