Tributes pour in for legendary literary agent Pat Kavanagh

To the Poet Laureate, Andrew Motion, she was "immaculate in her looks, her manner and her attention to detail", while to Margaret Drabble she was "vitality itself". For Joanna Trollope, she was both a "six-star class act" and clothes adviser.

These were just some of the tributes pouring in today for Pat Kavanagh, the legendary literary agent and wife of novelist Julian Barnes, who died yesterday from a brain tumour which was detected only a few weeks ago.

There was widespread agreement that literary London has lost one of its most illuminating individuals.

"I shall miss her shrewd advice, her enthusiasm, her dry humour, her warmth and her beauty," said Robert Harris, writing in the Times. In the Guardian, Clive James wrote: "She was beautiful, clever and loved to laugh."

South African-born Kavanagh was famously reticent about her age, which was 68 or 71, according to different accounts. She was among the founders of the literary agency Peters Fraser and Dunlop (PFD) where she assembled a stellar cast of writers, including Harris, Drabble, Motion, Ruth Rendell, Clive James, Sir John Mortimer, the estate of Laurie Lee, and, of course, Barnes.

She was adored by her writers for both her devotion to them and her straight-talking attitude, while publishers respected her literary tastes, while simultaneously being in fear of her formidable negotiating skills. "She could make publishers shake in their handmade shoes," said James.

Although she always tried to keep out of the limelight, the last year of her life was clouded by an extraordinary public dispute over her agency, which caused a bitter divide in the literary world.

Kavanagh had been responsible for leading the sale of PFD to the marketing and entertainment group CSS Stellar in 2001. Last year, unhappy at the way the agency was going, she and the same management team tried to buy it back. They failed and Kavanagh and many agents walked out.

The split led to 30 other agents, as well many authors and actors, such as Kate Winslet and Keira Knightley, moving with Kavanagh to found United Agency. PFD, left with only a handful of names, was bought by broadcaster Andrew Neil for a bargain £3.75 million. It is now run by Caroline Michel, the former head of the William Morris Agency. Several disputes over rights and back catalogues followed.

Kavanagh had an equally glamorous and sometimes controversial private life. She and Barnes, 62, who had no children, entertained many of their authors and other literary figures at their large home in Dartmouth Park in north London, with Barnes usually doing most of the cooking.

The marriage survived Kavanagh's affair with Jeanette Winterson, author of Oranges are not the Only Fruit, in the early 1990s. There was gossip about other relationships but to their friends, Barnes and Kavanagh were a devoted couple. Barnes's loyalty to his wife was most evident when his old friend Martin Amis left Kavanagh in 1995 for US agent, Andrew "The Jackal" Wylie. Barnes, incensed, severed all ties with Amis.

Kavanagh's brain tumour was said to have been discovered only recently. She was reported to have collapsed in the street two weeks ago and was being treated at the National Hospital for Neurology and Neurosurgery in London. Her closest friends and family had been told the tumour was inoperable.

Barnes, author of Flaubert's Parrot and Arthur and George, recently wrote of his own struggle to come to terms with death in Nothing to be Frightened of, which was published in March.

A statement by United Agency said: "Pat Kavanagh was an exceptional agent and a great friend. We all owe her a tremendous amount, she was an extraordinary presence who was much loved and will be greatly missed.''