The Pride of Baltimore, a sleek, 90-foot clipper ship reported four days overdue at Norfolk, Va., was still missing last night despite a two-day aerial search by the Coast Guard off the North Carolina coast.

Coast Guard officials called off their unsuccessful effort as darkness fell last night.A spokesman said the search would be resumed today for the handicrafted wooden ship and its crew of nine men and two women.

The ship, en route from Wilmington, N. C., was reported overdue on Wednesday by Norfolk city officials, who said the two-masted repplica of a 19-century clipper ship had failed to arrive as scheduled last Sunday.

The ship-equipped with a radio with a range of 30 miles-has not been heard from since April 5, when it departed the North Carolina port city for the voyage of approximately 300 miles up the coast.

Coast Guard officials said northwesterly winds as strong as 60 knots last weekened may have caused the ship, which is frequently overdue on voyages, to stray off course and out to sea. Yesterday, the Coast Guard extended its search to 180 miles offshore, scouring the Atlantic Ocean from Cape Hatteras to Chincoteague with one longe-range patrol plane and a helicopter.

The service also alerted sea-going vessels to keep a sharp lookout for The Pride.

The ship, built in 1976 at a cost of $475,000 as part of Baltimore's Bicentennial activity, was launched in May 1977 and has served as a seaworthy symbol of civic achievement. It is owned by the city of Baltimore and leased to Operation Sail, a local promotional organization.

Mayor William Donald Schaefer and Operation Sail manager Tom Norton told reporters yesterday that their concern will turn to "worry" only if the Pride of Baltimore doesn't turn up by the weekend.

"It's hard to believe that anything really bad happened to her," said Norton. "They know where they are. They're not lost."

But Norton added, "I would be seriously worried if she's not back by this weekened."

Norton said the ship was skippered by Charles Whitcomb, 52, of Cambridge, Md. an experienced sailor who helped build the topsail schooner. His crew of eight men and two women-all unmarried-range in age from 19 to 28.

"They've never gotten into port on time," said Louise Christmas of Monckton, Md. whose son Whitney joined the crew last August.

"Maybe I should be more concerned than I am, but the boat has hit a lot rougher weather than this and I suppose they're just off their course. I'm sure they don't think anybody's worried."

Chris Hartman, press secretary to Mayor Schaefer, said the vessel has been out of radio contact for periods as long as 10 days.

The ship was on the last leg of a 7,000-mile promotional winter cruise which included stops in various Caribbean ports. It arrived in Wilmington, N.C., last week for the city's azalea festival, during which visitors were allowed to board the green-hulled schooner. The vessel has no portholes, no shower and headroom of less than five feet below deck. The crew sleeps on hammocks slung inches beneath the crossbeams.

The ship was due in Norfolk on Sunday for a series of cocktail parties planned for Tuesday and Wednesday nights, and was scheduled to dock in Baltimore this Saturday.

Tim Jones, Norfolk's special events coordinator, said he did not become concerned about the overdue clipper until Tuesday, when he tried unsuccessfully to reach the Pride by marine radio. Jones called the Coast Guard on Wednesday, touching off the search.

The ship, which left Baltimore last Oct. 16, is equipped with a "very small" 85 horsepower diesel auxilliary engine used mostly for docking, Norton said yesterday. At sea, it depends entirely on sail power.

It also carries a radio with a range described by officials yesterday as 20 to 30 miles "at best."

"That's more than Columbus had," said once Coast Guardsman yesterday.

At a press conference in Baltimore, Mayor Schaefer said his office had received "many expressions of concern" from local citizens. Schaefer said a businessman, who asked for anonymity, had offered to raise money in the Baltimore business community to buy a long-range radio telephone for the vessel.

"That $5,000 (for the radio) is a lot of money," Schaefer said.

Schaefer also said the Pride of Baltimore was not equipped with radio rescue beepers, devices that send out distress signals in case of sinking, but said the equipment would be provided when the ship returns.

The ship is scheduled to depart Baltimore on May 13 for a trip to Canada.

For the last two years, the ship has been a showpiece at races and maritime festivals up and down the Eastern seaboard.

It visited Washington in September 1977, tying up at the Maine Avenue waterfront for a week-long open house.

Modeled after the sleek Baltimore clippers which served as pirate ships, slavers and as gun-runners during the War of 1812, the Pride was designed by Annapolis shipbuilder Melbourne Smith. Smith relied on French and British maritime history books for the design. No blueprints were ever made of the famous coastal ships.

When fully rigged, the two-masted schooner carries seven sails and has a total sail area of 9,523 square feet. Her top speed is 12 knots, considerably faster than other sailing vessels of her size.

The ship was the first authentic Baltimore clipper built inmore than a century.

One official said yesterday Operaion Sail has a waiting list of over 100 people, anxious to become crewmembers who are paid an average of $15 per day.

"The thing that's fun about a ship like this," Melbourne Smith told an interviewer in 1977, "is that there's nobody alive who ever sailed one or knows how to. You have to discover everything yourself." CAPTION: Picture, The Pride of Baltimore, a replica clipper ship, has been missing for four days and is believed off course. AP; Map, Broken line shows clipper's route. By Richard Furno-The Washington Post