Virginia Gov. John N. Dalton (R) last night offered the City of Alexandria any assistance necessary to resolve the six-year-old federal suit that has blocked major waterfront development in the city for several years.

Dalton told about 60 Republicans at a campaign rally in Old Town that has ordered state Attorney General J. Marshall Coleman to monitor the legal proceedings underway with federal officials and give help if necessary.

"I share your sense of frustration over the delays and expense that this federal interference has caused," Dalton told the Republicans.

Coleman, also a Republican, told the group he soon will set up a procedure for dealing with local officials on the subject. He added that "until recently I didn't even know about" the suit, which was filed in 1973.

Dalton's offer was immediately criticized by some Democratic members of the Alexandria City Council. "He is a day late and a dollar short," said two-term member Donald C. Casey. "where was he when we needed him before? This is nothing but a campaign ploy."

Mayor Charles E. Beatley Jr. said, "I would be surprised if we need his help now. I would thank him for his offer, but tell him to stand aside because we have got his thing moving," he said.

Although the State of Virginia was named as a defendant in the original suit, city officials yesterday said they have never received any help, or even the offer of help, from state officials in Richmond.

Last Friday Beatley and other city officials met with federal representatives regarding the suit, in which the U.S. government claims ownership of the 50-acre waterfront. One result of that meeting was a proposed agenda for discussion between the two sides that could result in an end to the suit by early summer.

Vice Mayor Robert L. Calhoun said last night that after the Friday meeting, "We tried to fill him [Dalton] in. We are interested in having the state participate, if necessary."