LONDON -- Britain's new prime minister, John Major, opened his administration yesterday with pledges to build "a society of opportunity" at home and to play a "full and leading" role in developing European unity abroad.
Immediately after being asked by Queen Elizabeth II to form a new government, Mr. Major:
* Paid tribute to his predecessor and political patron, saying: "I am grateful for the enormous achievements that I inherit from Margaret Thatcher. I think history will record that she was a towering prime minister who left our country in a far better condition than she found it 11 years ago."
* Appointed a Cabinet dominated by men of his own age, representing a generational restructuring of government as much as a reshuffling of portfolios.
* Set out his ambition to "build a country that is at ease with itself, a country that is confident and a country that is prepared and willing to make the changes necessary to provide a better quality of life for all our citizens."
* Expressed his enthusiasm for the "full opening and flowering of the single market in Europe."
* Authorized the reopening of diplomatic relations with Syria, broken four years ago after Syrian diplomats here were deemed involved in an attempt to plant a bomb on an Israeli airliner at Heathrow Airport. The British government accepted Syria's rejection of acts of international terrorism and willingness to take action against perpetrators.
As he formed his government, Mr. Major confronted a series of problems, dominated by the Persian Gulf crisis, in which he will hew closely to Mrs. Thatcher's staunch support of the Bush administration's policy, and an economy in recession, which he will try to treat by continuing to squeeze out inflation.
The former chancellor of the exchequer became leader of the Conservative Party and thereby prime minister when his two challengers withdrew after Tuesday's ballot, in which he gained a commanding lead over Michael Heseltine and Douglas Hurd.
Mr. Heseltine, 57, who resigned as Mrs. Thatcher's defense secretary in 1986, returns to the government as Mr. Major's environment secretary. This will put him in charge of the unpopular poll, or head, tax, which Mr. Major has promised to review.
Mr. Hurd, 60, remains as foreign secretary.
In a third significant Cabinet appointment, Mr. Major named his deputy at the Treasury, Norman Lamont, 48, who headed his leadership election campaign, to be the new chancellor of the exchequer.
Finally, he chose a colleague from his own parliamentary "class of '79," Chris Patten, 46, previously environment secretary, to become Conservative chairman, charged with healing the wounds of the recent internal conflict.
At 47, Mr. Major is the youngest prime minister this century. Opposition Labor leader Neil Kinnock is 48.
Mr. Major's election also continues the retreat of Conservative leadership from the privileged classes in which the party has its roots. Mrs. Thatcher was the daughter
of a grocer; her predecessor, Edward Heath, was the son of a builder.
Mr. Major, a tall gray man in owlish spectacles, quietly spoken and darkly dressed, stated his priorities in a brief statement on hTC the doorstep of 10 Downing Street. His wife of 20 years, Norma, a former home economics teacher, was at his side. Their teen-age son and daughter were not present.
"I certainly hope . . . to build a society of opportunity. By that I mean an open society, a society in which what people fulfill will depend upon their talent, their application and their good fortune."
Noting the end of the Cold War and the prospect of the "flowering of the single market in Europe," he predicted that the 1990s would be "a decade of the most remarkable opportunities."
In one of the most significant paragraphs, he said: "We have in front of us the building and development of an entirely new Europe, a building and development in which this country will play a full and leading role."
This signaled a radical departure from the strident negativism Mrs. Thatcher employed against plans for European unity. Colleagues of Mr. Major said they expected the more cooperative approach to be on display at next month's intergovernmental conferences in Rome, which will seek to foster political and economic union.