Pan American World Airways has a definite "interest" in acquiring the Willard Hotel here in Washington, William Seawell, Pan Am's chairman and chief executive officer, said yesterday.

At the airline's annual meeting and a press conference following it, Seawell said one of the carrier's priority objectives was the "sensible expansion" of its Inter-Continental Hotels into the major U.S. cities the airline serves. "We would like to have an Inter-Continental Hotel in all our gateway cities," he said, naming New York, Washington, Houston, Los Angeles and Seattle.

Pan Am's wholly owned hotel subsidiary already has two hotels in the continental U.S.; the Mark Hopkins in San Francisco and the Four Ambassadors in Miami. Profits for the subsididors in Miami. Profits for the subsidiary, which has a total of 80 hotels in 48 countries, nearly doubled in 1977 to $11.4 million, Seawell noted.

Although said he didn't think a redevelopment decision by the Pennsylvania Avenue Development Corp., which now has title to the historic Willard Hotel, is imminent, he said "we intend to express our interest . . ."

Although Pan Am sometimes has built hotels, it also has taken some landmark buildings - one of them in Paris - and renovated them into first-class and luxury hotels, he noted.

Seawell noted there was no timetable for acquisition of the hotels and Pan Am had turned down several opportunitise to purchase properties in New York "because we didn't think we could make any money on them."

On other items, Seawell said Pan Am:

Is not now considering moving its headquarters from New York City although he has received a study he commissioned on the "economic pros and cons" of moving. It is not "an active question" because there are other "more important" items on Pan Am's agenda, he said, adding that he probably will look at it more seriously next year.

News of Pan Am's possible consideration of leaving New York had brough a visit from Mayor Edward Koch, who was "quite interested" in improving the business climate for Pan Am, Seawell said "and we will see what happens."

Seawell noted that Pan Am would like to see IATA separate the trade association functions from those of the traffic conferences which set fares for geographic areas; the U.S. flag carrier also would like the flexibility to opt in or out of specific conferences, he said.

At a directors meeting preceding the annual meeting, held in the Eisenhower Theater of the Kennedy Center, Dan Colussy was elected president and chief operating officer to succeed F.C. (Bud) Wiser Jr. Colussy was most recently executive vice president for marketing and services. Also yesterday, William Waltrip was elected to the post vacated by Colussy.

Shareholders were greeted outside the Kinnedy Center by a dozen members of the Independent Union of Flight Attendents carrying picket signs. Entering negotiations for a new contract, the flight attendants say they are seeking better working conditions on Pan Am's long-distance flights, such as bunks for rest periods.

Questioned by several flight attendants who are stockholders, Seawell said he would take their concerns "seriously" and try to come up with "sensible" solution.