NAPERVILLE, Ill. (AP) -- Natural gas distributor Nicor Inc. on Friday said its subsidiary will buy a Miami shipping company.

The unit, Birdsall Inc., signed a deal to buy Deluxe Freight, which primarily serves the Cayman Islands. Terms of the deal were not disclosed.

Birdsall is the parent company of Tropical Shipping, which ships containerized freight in the Bahamas and Caribbean.

Deluxe Freight operates in the less-than-container load and full-container load market. Its headquarters will remain in Miami and the company will operate as a separate brand led by current President Willie Munoz.

Tropical Shipping Chairman and President Rick Murrell said the Cayman Islands is a key market for the company. "While the acquisition is small in relation to our total volumes, the Deluxe brand addition expands our service offerings in a market that is important to our long-term success."

Nicor shares closed Friday down 11 cents at $38.34.