Britain clasped its hands together and gave a collective coo of approval today as Buckingham Palace announced the engagement of Prince Andrew, Queen Elizabeth's second son and long considered one of the world's most eligible bachelors, to Sarah Ferguson, a 26-year-old blue-blooded commoner.

Andrew, also 26, and his bride-to-be appeared together for photographers in the palace gardens and in a televised interview shortly after word of their betrothal officially was released at 11 a.m. They said they were "over the moon" with happiness.

Although he cautioned that conflicting royal schedules may delay the wedding until fall, Andrew said they hoped it would take place in July or August at Westminster Abbey, where his parents were married in 1947 and his sister, Anne, in 1973. The last royal wedding, joining his elder brother and heir to the throne, Prince Charles, and Diana Spencer in 1981, was held in the much larger St. Paul's Cathedral in what was considered somewhat of a break with tradition.

Sarah said she wanted the wedding sooner, rather than later. Displaying an informal and outspoken style that commentators here labeled "refreshing," she interrupted Andrew's somewhat halting explanation of their uncertain timing to tell an interviewer she wanted to "get on with it."

As she kissed her fiance' for the cameras, Sarah showed off a large diamond and ruby engagement ring, which she noted matched her flaming red hair. She said she intended to keep her job at a London graphic arts company after her marriage, when she will be known as "Her Royal Highness the Princess Andrew."

Hundreds of people had gathered outside Buckingham Palace this morning to await the long-anticipated announcement. It came in a one-sentence letter on the queen's stationery, in which she said she and her husband Prince Philip, the Duke of Edinburgh, were "greatly pleased." Copies were unceremoniously handed out at the palace gate by a royal staff member.

Sarah's father, gentleman farmer Maj. Ronnie Ferguson, said he too was pleased with the match. He pronounced Andrew, a navy pilot, "a real man, regardless of whether he's a prince or anybody else."

Both the BBC and independent television went on the air almost immediately to deliver the news and devoted most of their midday programming to the announcement. Two television representatives were invited inside the palace, and their interview with the couple was broadcast repeatedly throughout the afternoon.

In that interview, Andrew and Sarah agreed that despite being acquainted since they were children, they never really noticed each other until last summer. It was then that Sarah -- at Diana's urging -- was invited to accompany Andrew to the Royal Box at Ascot. Even then, it took some time for sparks between them to flame.

Several weeks ago, during a private weekend in Scotland, Andrew got down on both knees and proposed, they said today. She accepted, he said, but warned him to sleep on it overnight in case he changed his mind. He didn't.

Under British law, however, an official betrothal had to wait for the approval of the monarch, who at the time was visiting Australia and New Zealand. Queen Elizabeth returned last Friday and gave her blessing.

Despite the obvious comparisons with "my very, very good friend" Diana, Sarah today seemed markedly more at ease than was the now-princess during similar circumstances following the announcement of her engagement to Charles. In her own engagement interview, Diana barely spoke, kept her eyes downcast and seemed terrified.

Both Sarah and Andrew today seemed in exuberant spirits, laughed openly together at both the questions and their own answers, and displayed a bit of their individual personalities and the nature of their relationship.

Asked what they saw in each other, Andrew hesitated. "Oh, um," he fumbled, before Sarah turned to her future husband and prompted, "Wit? Charm?"

"Yes, probably," he said. "And the red hair."

"And the good looks," she said, rolling her eyes and making a face. Laughing loudly, she reached out and grabbed his arm before glancing back at the interviewer sheepishly and composing herself. "Whoops. Sorry."

The interview was shown along with documentary biographies of Andrew and Sarah, as well as reactions of commentators ranging from the bartender in Sarah's home-town pub to members of Parliament.

Reaction from the latter was varied. Harry Greenway, a Conservative member, tabled a House of Commons motion congratulating the couple and wishing them "joy, a long life and happiness." But antimonarchy Labor MP Willie Hamilton grumpily rejected that idea and advised Parliament to "just forget about it."

Overall, news of the engagement was greeted with widespread delight by a nation that considers members of the royal family its biggest celebrities and watches their every move with a level of attention surpassing that devoted to television soap operas. Both the BBC and independent television broadcast special programs rerunning the royal interview and documentary biographies of the two.

Many a maiden's heart is likely to be broken by the ending of Andrew's bachelor days. But matrons across the land will breathe a vicarious sigh of relief that the queen's handsome and rambunctious son, whose previous liaisons with soft-porn starlets and models have been well publicized, finally has chosen a suitable mate.

Fred Oxer, the 64-year-old gardener at the Ferguson family estate in Hampshire, reflected a popular view of Sarah when he told reporters today: "She is a good girl, a very nice girl."

Although she is technically a commoner, strong blue blood runs through Sarah's veins. Burke's Peerage pointed out she has more ties to the ancient and royal families of the country than does her future husband. She is a direct descendant of Charles II (with his mistress Lucy Walters). Sarah and Andrew are sixth cousins, sharing common ancestors in the fourth Duke of Devonshire and his wife, Lady Charlotte, dating from the mid 18th century.

A Burke's news release noted that Sarah's "private life" has been "unorthodox," an apparent reference to previous long-term relationships with at least two other men.

Ominously vague, Burke's warned that "the marriage . . . will open up a Pandora's box of problems that will alter Royal etiquette and protocol beyond all recognition. The only first left for the Royal Family will be for one of their number to remarry after a divorce."

Although Andrew is only fourth in line for the throne, behind Charles and his two young sons, Burke's raised an indirect comparison to the storm caused by Wallace Warfield Simpson, the American divorce' for whom King Edward VIII abdicated in 1936.

A more felicitous and frequent comparison was made between Sarah and her future sister-in-law, Princess Diana, who is held responsible for promoting the romance with Andrew. Both are considered "modern" women who can breathe some fresh air into the stodgy royal atmosphere.

Like Diana, Sarah grew up inside the charmed royal circle. She probably first met Andrew, her now-divorced parents agreed today, at the age of 4 or 5. "I think the first time that I can remember," said her mother, Susan Barrantes, "was on the polo grounds. The usual place where everybody meets."

In fact, although neither Andrew nor Sarah appears personally obsessed with the game, their lives seem to have been wound together by the British aristocracy's fascination with polo. Sarah's father played with Prince Philip, and the two used to bring their children along to the matches. Ronnie Ferguson now serves as Prince Charles' "polo manager."

After leaving Ferguson when Sarah was 14, her mother married Hector Barrantes, an Argentine polo player. In the view of some optimists here, the Sarah-Andrew relationship could lead to a thaw between Britain and Argentina, who fought the Falklands War in 1982. A helicopter pilot who came under fire several times, Andrew emerged a hero from that conflict.