George III lost the Colonies 201 years ago this weekend, but Robert Morley is doing his best to lure the colonists home. Not even Elizabeth II is a more ubiquitious electronic visitor to American homes than this actor who merrily makes TV and radio commercials for British Airways.

"We've all heard the line: "Now a message from Mister Robert Morley," and while no one can be certain how many round-trip tickets the suave actor has sold for British Airways or nudged into sea-air trips with Cunard, obviously they're flowing like North Sea oil. This is Morley's sixth year, so the shill game must be working.

There's a side effect to Morley's ambassadorial role. Along the Strand pass thousands of visitors who've met Morley in their living rooms. Above the automobile passage to the Savoy Hotel and its Grill, much favored by well-endowed Yanks, there's a discreet electric sign: "Robert Morley and Julian Orchard in 'Banana Ridge.'"

The Savoy and its adjoining theater were created by Ruper D'Oyly Carte from the profits of the Gilbert and Sullivan operettas, hence the term Savoyards for Gilbert and Sullivan fans. Like so many London theaters, the 1,132-seat auditorium is largely underground.

No surprisingly, many American are in the filled house the night before the queen's big parade; Morley's "guests" want to see him in the flesh. Between them Morley and Orchard, a TV favorite known for his Les Dawson series, give adroit farcical performances in the 14th month of their run.

To get to Morley's dressing room one climbs from the stalls a couple of levels below ground to street level and, in an alley in back of the hotel, goes down tortuous passageways backstage to Dressing Room No. 1, traditionally on stage level. Morley has had this room for long runs in "The Man Who Came to Dinner," "A Ghost on Tiptoe" and "The First Gentleman," which means that for six years of his 69 he's been resident of Savoy Dressing Room No. 1, a minor but impressive record for the Guinness book.

He's over 6 feet tall and moves more lightly than his weight might suggest. On the dressing room TV screen Nureyev is dancing a Jubilee salute, taped, from a few nights earlier, at the Olivier Theater. Morley is genuinely pleased to share the city's current Jubilee excitement and amused that a Yank drama critic wants to talk about his British Airways commercial.

"Larry turned it down when he got the first offer," Morley remarks, meaning that Laurence, Lord Olivier, had not felt he was right for the part. "Larry is working very hard to create an estate for his young children's education but he felt this was out of his line. Six years ago we had no idea whether it would succeed. Apparently

"We film new 60-second spots two or three times a year and tape radio spots more often. British Airways is adding cities to its American flights and we make special ones for each.

"The scripts are supplied but I'm permitted to twist them about for my own style. Some, I'm sorry to say, haven't worked out. There was a whimsical one about filching the Crown Jewels from the Tower of London I was sorry they didn't use. Bad behavior pattern? Another about Benjamin Franklin's kite and key I liked. Perhaps they'll use it yet. My line "Big podden, Ma'm" was okayed without a quibble. One never can be sure about commercials and all the people who must approve them."

For all his 40 years as a star, Morley is robust and active and his movements always have been more deliberate than slow. His light blue eyes look intently at his visitor while his words race along, swift, allusive and lively. For Morley the acting hours of his day are only a small part of his crowded routine.

He writes several times a month for Punch, usually about cuisine though he can take off on any topic that amuses him. His nimble mind is valued for the talk shows and he turns down more movies than he accepts. He's been writing plays and books for 40 years, has served on the Actors' Equity Council and is now working on a new book, proceeds of which will go to a foundation for autistic children.

"I'm calling it 'Robert Morley's Load of Bricks,' meeting those ghasty blunders we all make for highly embarrassing moments. Not long since I was holding forth on what was wrong with a particular play. Turned out I was talking to the author. I'm collecting these from friends and believe it will be an anthology of true, terrible accidental humor."

Is he also writing a play? Morley is off on another topic but one recalls that it was "Edward, My Son," written with Noel Langley in 1944 and a Broadway hit of 1947, which put Morley on the American map, though he had appeared here just before World War II as Oscar Wilde. Altogether "Edward My Son" took five years of his stage time on three continents.

Son of an Army officer, Morley originally was slated for a diplomatic career but he sidetracked to a course at RADA, the Royal Academy of Dramatic Art. Small parts, assistant stage manager jobs and tours with Frank Benson's Shakespeare company led him quite speedily into leading character parts. He's been Henry Higgins in "Pygmalion," George IV in "The First Gentleman" and Sheridan Whiteside of "The Man Who Came to Dinner." He prefers to forget his only musical. "Fanny," and one he wrote titled "Hook, Line and Sinker."

Through the years there have been scores of movies, among them "Major Barbara," "The African Queen," "The Doctor's Dilemma," "Topkapi," "The Daring Young Men on their Flying Machines" and "The Loved One." He finds time to act on television after introducing a precedent-setting series called "Bringing Up Parents." He's married to Joan Buckmaster, daughter of Gladys Cooper. Their son, Sheridan, married to a woman from Boston, is drama critic for Punch, a TV personality and author of "A Talent to Amuse," a biography of Noel Coward. I remark on Sheridan's erudition. "He must have had a fine education."

"Not at all," says father Robert. "I don't believe much in formal education. D'je ever notice how stuffy formal education makes some people, dogmatic in their thinking? No, what Sheridan has learned he's learned on his own and neither I nor the British educational system can take any credit for it.

"So many things aren't what they seem. You always have to think twice. At least. Take the recent strike at the National Theater, stemming from the firing of a plumber. Seems absurd. The public impression is against the plumber and striker. Yet what lies behind it is far more complex - resentment of the higher-ups getting a good deal of money and perks. Peter Hall, the National's director, is paid a very good salary in that post and is given fancy living quarters in posh Barbican Tower. But he takes a good many side jobs at high fees on the side. The feeling of the workers, some of whose hobs are being abolished for economy reasons, is that they are getting a very short end of the stick. That's what's really behind the strike."

Morley shows no heat or anger discussing public problems affecting his profession. He states them simply as independent views that experience has led him to form within. It is characteristic of him to face life with calm, reasoned detachment. He seems to relish feretting out independent attitudes, and minority positions do not frighten him.

"Generally," he remarks, "I'm on the side of the young or the unknown because their viewpoint is fresh, giving perspective to those of us who've been in for a while."

You get the feeling that Morley is exceptionally well organized, a star who doesn't limit his work to performance hours. The Morley home is a Berkshire "cottage," about an hour's drive from London. With his chauffeur driving, Morley naps both ways, which is why he can be the West End star at midnight and the country squire at 8 a.m. What he seems to do with effortless ease actually is a carefully studied, disciplined routine, a performance in which the private man has become a charismatic public image.

British Airways casting directors may not have known exactly what they wanted, but Morley's private self has created a character that jibes perfectly with what Americans think Britons should be: worldly, witty and slightly aloof, eccentric in the grand manner.