NEW YORK (AP) _ In establishing one of the world's major communications empires, British publisher Robert Maxwell has turned around ailing enterprises through drive, imagination and heavy arm wrestling with unions.

When the ailing New York Daily News could not wrest key concessions from its striking unions, the way was opened for the beefy, bushy-browed Maxwell to try to realize his long-held ambition of acquiring an American newspaper.

The parent Tribune Co. signed a letter of intent to sell the tabloid to Maxwell, making him the last hope to avoid a shutdown of the 71-year-old paper.

Maxwell announced the agreement to save the newspaper Tuesday afternoon.

Although he has not had a big dispute with British press unions recently, Maxwell faced them down repeatedly in the mid-1980s, closing or threatening to close publications unless they agreed to longer work weeks and pay and job cuts.

When he bought the failing British Printing Corp. in 1981, Maxwell cut 6,000 of 13,000 union employees and modernized production. He had it turning a profit within two years and under the name British Printing & Communications Corp. it is Britain's biggest printer.

His first newspapers were the Daily Mirror and the five other papers of the Mirror Group, which he bought in 1984. He cut the staff from 6,000 to 4,000 and turned the holding around in what a financial-press executive called ''the greatest business achievement on Fleet Street in a quarter of a century.''

To succeed against the bigger daily Sun of his archrival, Rupert Murdoch, Maxwell threw himself personally into day-to-day operations of the Mirror, editing copy, writing headlines and contributing editorials under the name Charles Wilberforce.

A union leader once said Maxwell ''could charm the birds out of the trees, then shoot them.''

That went for managers as well as laborers.

After his London Daily News, founded in 1987, turned into a five-month, $50-million flop, Maxwell declared: ''I made certain that never again would I launch a paper and leave it in the hands of the professionals.''

He launched The European - a kind of USA Today for the continent - last May, and then discovered there was no office for him in its newsroom. He immediately plucked the nameplate from the door of the editor's office and took it over.

''My primary duty is to hire and fire editors,'' he once told an interviewer. ''I treat them like a field marshal.''

His adversaries have pictured him as an unsavory interloper, his tactics too aggressive, his pay too low and his products too costly.

His personal fortune has been put at over $1 billion and his businesses are based in 16 countries and pull in $1.7 billion a year.

Maxwell, 67, says his is one of a few companies ''with the resources to play communications vertically, from pulp at the foot to satellites at the top, and to play it on a global scale.''

He travels with a personal photographer and uses a helicopter to channel hop or to commute daily from his country estate to London. For long trips he has a private jet.

He was born Jan Ludwig Hoch, son of poor Jewish farm workers in Czechoslovakia on June 10, 1923. He received only three years of formal schooling, but absorbed a Socialist philosophy at his mother's knee.

He fought Hitler as a teen-age member of the Czech underground and the French Resistance and finally as a decorated, field-commissioned captain in the British Army. His war service was performed under various names and he settled on Ian Robert Maxwell in his adopted country.

While working for the occupying forces after the war, Maxwell recognized that a treasure existed in the backlog of unpublished German scientific and technical papers.

He returned to England and made his first millions through Pergamon Press, publishing trade journals and scientific books.

In 1964 Maxwell was elected to Parliament as a Laborite, but his political career ended in 1970, in part because of questionable dealings involving Pergamon.

He allegedly misrepresented the company's value to a buyer and the Department of Trade and Industry concluded after an investigation that he was not someone ''who can be relied on to exercise proper stewardship of a publicly quoted company.''

In the United States, Maxwell acquired a string of printing companies and became the nation's No. 2 printer, rolling off such publications TV Guide, Parade magazine and several Time Inc. titles.

He sold the company, Maxwell Graphics, to a Canadian corporation for $510 million in 1990, about 1 1/2 years after paying $2.5 billion for Macmillan.

Maxwell had lost out to Murdoch in London in 1968 when both sought to acquire the News of the World, a Sunday tabloid. Maxwell also lost the Sun to Murdoch and in succeeding years he made unsuccessful tries for the Evening Standard, the Times of London and the Observer.

Maxwell has been married since 1945 to French-born Elizabeth Meynard. Most of their seven children work for their father, with two sons, Kevin and Ian, in key jobs.