WILLIAM McIlvanney's agent has spoken of his "warmth and humanity" as tributes continued to be paid to the author, writer and poet who died aged 79.

McIlvanney, hailed as one of the most important literary Scottish voices and an inspiration to a generation of writers and readers, died after a short illness at his home in Glasgow.

Jenny Brown, McIlvanney's agent in recent years, said that he had been loved by his many readers, and "for such a long time".

Ms Brown said that in particular his success of recent years, when his books were re-published by Canongate, had brought much joy to the writer whose birthday was only celebrated two weeks ago.

"It is a very, very sad day indeed," she said.

"It is moving to see all the tributes. And it was also fabulous that at least Willie was able to feel cherished and feel that his writing was still held in such high regard, especially since re-publication.

"I am so pleased he was able to receive awards in recent years, like the [Saltire Society's] Fletcher of Saltoun Award in 2013. It meant a great deal to him."

McIlvanney had enjoyed literary trips to Spain, Germany and France in recent years, she said, and only last week a deal for a Turkish edition of Laidlaw was finalised.

He was working on new work, including new crime fiction and an autobiographical work, arts funders Creative Scotland said.The Herald: Author William McIlvanney at the Edinburgh Book Festival 2009.. (48572963)

Ms Brown said she particularly remembered his warm interactions with readers, keen to listen to either "street reviews" or at book festivals.

"I loved working with him," she said. "To speak to him I either had to pick up the phone or write to him - that was just the way he worked. You always felt that warmth and humanity."

One of Scotland's leading historian, Professor Tom Devine, said he was deeply saddened by the news.

He said: "The nation has just lost a great Scot.

"Willie was a great man of many talents: a hugely gifted writer, perceptive journalist, eloquent speaker,wonderful company and a truly charismatic personality.

"I counted him a friend.

"The prayers of my family and myself go out to Siobhan, his children and grandchildren at this sad time. Willie, you will be remembered. Requiescat in Pace."

The First Minister of Scotland, Nicola Sturgeon, has paid tribute. "I am extremely sad to hear of the death of Willie McIlvanney.

"His writing had a huge influence on me when I was growing up.

"Docherty, in my view, is one of the classic novels of our time. Willie came from Ayrshire – as I do – and had taught at my school in the years before I went there, so he was something of a local hero. I will always remember the thrill of eventually getting to meet him some years later."

She added: "Willie’s passion for social justice and for Scotland – warts and all – shone through all of his work.

"His description of Scotland as a ‘mongrel nation’ powerfully summed up our wonderful diversity as a country. Willie was an iconic figure in Scottish literature and deserves to be remembered as one of our literary greats."

A spokesman for Creative Scotland, said: "We are deeply saddened by the news of William McIlvanney’s passing. He was a true giant of Scottish literature, a great writer, poet and thinker.

"Ill health prevented him from travelling with a delegation of Scottish writers to the Pisa Book Festival in November, but he was able to join the Italian audience via video link and was as witty, acerbic and honest as he has always been in his writing.

"He had many projects planned, including new crime fiction and a larger, auto-biographical work he had originally conceived with the help of Creative Scotland’s then Head of Literature, the late Dr Gavin Wallace.

"This recent surge of creativity would have been a wonderful addition to his already rich contribution to the Scottish canon. "The Herald: William McIlvanney Scottish Crime Writer and poet photographed in Glasgow city centre on the eve of the reissue of his novels fron the 1970's..28/03/13.Pictures Kirsty Anderson Herald & Times. (48542442)

Many authors expressed their grief at the news.

Ian Rankin described his death as "dreadful news".

He said: "A truly inspired and inspiring author and an absolute gent."

Irvine Welsh said: "Absolutely gutted to hear this. An inspirational writer and one of the loveliest guys you could hope to meet."

Christopher Brookmyre added: "Raising a glass to William McIlvanney tonight. An inspiring writer, a generous spirit, a commanding voice and a privilege to have known."

Val McDermid wrote on Twitter: "I've just heard the heart-breaking news that Willie McIlvanney has died. He showed so many of us Scottish writers what was possible."

For many years an English teacher, McIlvanney gained recognition as a major writer with the publication of his first novel, Remedy is None.

His reputation grew with works such as The Big Man, The Kiln and his Laidlaw trilogy, which are now credited with being pivotal works in the development of 'Tartan Noir'.

Jamie Byng, of Canongate Books, said: "I am so sad that the incomparable William McIlvanney is dead. But his great books and his memory will live forever."

The publishing house said: "McIlvanney was a writer who inspired a generation.

"Docherty and the Laidlaw series have, amongst others of his books, left a major and lasting impression on the literary landscape.

"We are enormously proud to publish him, and will miss him hugely now he is gone."

The Edinburgh International Book Festival, at which he appeared many times, said: "A sad, sad day for Scottish literature indeed. Devastating news. Our thoughts are with William's family and friends."