New British Prime Minister John Major named the man he defeated in the battle for the job, Michael Heseltine, to his Cabinet Wednesday, a government statement said.

Major promised Wednesday to work for a better life for all Britons and said Britain would play a "full and leading role" in European development."I want to see us build a country that is at ease with itself, a country which is confident and a country that is prepared and willing to make the changes necessary to provide a better quality of life for all its citizens," Major told reporters in his first public comments as prime minister.

Heseltine becomes environment minister. Norman Lamont fills Major's previous post as chancellor of the exchequer (finance minister). He had been No. 2 at the finance ministry.

Douglas Hurd, who also stood in the ballot for leadership of the ruling Conservative Party against Major, remains foreign secretary.

Tom King remained defense secretary. The decision to keep Hurd and King in their jobs appeared to signal continuity in British policy in the gulf crisis.

As environment minister, Heseltine will have a chance to conduct a review of the unpopular poll tax, a levy to pay for local services introduced during Margaret Thatcher's premiership.

In his campaign for the Conservative leadership, Heseltine pledged such a review.

Chris Patten moved from the environment ministry to become Conservative Party chairman with the job of healing wounds caused by the leadership struggle and getting ready for the general election Major must call by mid-1992.

Major, at 47, is Britain's youngest prime minister this century. He paid tribute to Margaret Thatcher, whom he served under as chancellor of the exchequer until Wednesday morning's visit to Buckingham Palace where Queen Elizabeth II asked him to form a government.

"I think history will record that she (Thatcher) was a towering prime minister who left our country in a far better condition than she found it 11 years ago," he said, a day after the ruling Conservative Party elected him as its new leader.