Argent Marine Services Inc. filed a lawsuit Thursday against the Maritime Administration's decision to cancel an agreement to sell three liquefied natural gas tankers to Argent subsidiaries.

"There is no question that the Argent Marine companies and all of their officers, directors and shareholders are and always have been U.S. citizens" and therefore should have been found eligible to buy the vessels, said Stephen P. Gottlieb, president of Argent Marine Services Inc., New York City.Marad officials had not yet seen the lawsuit and declined any immediate comment Thursday.

Earlier this month, Marad reneged on an agreement to sell the vessels to three San Francisco-based Argent subsidiaries - Argent Marine I, Argent Marine II and Argent Marine III - for about $12 million each.

The ships, the Arzew, Gamma and Southern, have been inactive since 1981. Marad had approved the companies' U.S. citizenship in an option agreement negotiated in 1988.

The Argent suit, filed in federal appeals court in Washington, said Marad's action rescinding the agreement jeopardizes the delivery of natural gas to the United States and prevents the reopening of the Cove Point LNG Terminal on Maryland's Chesapeake Bay.

The suit seeks to set aside Marad's decision and block Marad from terminating the contractual rights of the Argent subsidiaries. The option expires April 5.

The Argent companies have a charter agreement with Royal Dutch Shell to transport gas between Algeria and Cove Point, and Nigeria to the U.S. East Coast and Europe. Marad's decision on citizenship was based largely on that relationship.