Thanks to the generosity of a Canadian financier, the new wing of Bermuda's National Gallery will be opened on Thursday, far ahead of the original schedule.

Named for its benefactor, Mr. Christopher Ondaatje, the $250,000 addition will house the Historical Bermudiana Collection, showing items that, until now, have been retained for safekeeping in the National Archives.

In addition to footing the bill for the impressive, tray-ceiling, 50-foot long gallery, Mr. Ondaatje is also donating the Bermuda proceeds of his latest book to the Masterworks Foundation. For, some years ago, wearying of the world of commerce, the self-made millionaire went off in search of leopards in Africa and, more recently, to Sri Lanka -- which has led to a totally new career, that of writer and photographer. The result is his new book, The Man-Eater of Punanai, which will also be officially launched at Thursday's opening of the Ondaatje wing.

Mr. Ondaatje was born in Ceylon (now Sri Lanka) and educated in England before going off to Canada as a young man with just 12 in his pocket. After amassing a fortune in investment banking and publishing, he finally returned to his island home some forty years later. His search there for the ghost of a legendary man-eating leopard became the metaphor for his own journey of reconciliation with his father, whose self-destructive behaviour had led to the financial ruin of his family.

He found the Sri Lanka of today very different from the utopian isle he had left as a child. Speaking from his Toronto office last week, Mr. Ondaatje said: "I was lucky enough to have been born on a paradise island, Sri Lanka, which is very similar to that of Bermuda. Sri Lanka is an island with beauty, culture and history which, unfortunately, is being rent apart now in a terrible civil war. All of us should probably learn a lesson from this. The world is changing now and is in the throes of quite a serious recession and if we don't all learn to live with ourselves in harmony, there will almost certainly be tragic consequences.'' Mr. Ondaatje, who bought a home here in 1978, said: "As far as my wife and I are concerned, Bermuda is home for us. We started coming here in 1970 and have been back three or four times a year ever since. We have been residents for nearly 14 years and we will always be fully committed to and supportive of all the arts on the Island, particularly the Bermuda National Gallery and the Masterworks Foundation.

"There is no doubt that every mature country needs a permanent home for its art. Otherwise, it will be impossible to maintain or collect valuable treasures that belong to and are a heritage of Bermuda. The National Gallery now finally is the home for these treasures and everybody on the Island can enjoy them.'' Chairman of the gallery, Mr. Jay Bluck, said that the new Ondaatje wing was important because it would mean that works of art and crafts relating to Bermuda's historical past would at last be accessible to the people of Bermuda. Until now, due to lack of climate-controlled facilities, these have been stored away for safety in the National Archives. Mr. Bluck said that in future, the gallery will be working closely with archivist Mr. John Adams in arranging rotating exhibitions of "historical Bermudiana'' for the benefit of the general public.

"We are very grateful to the Ondaatje family,'' said Mr. Bluck, "this gesture is another wonderful example of non-Bermudian residents making fabulous contributions to this Island. We also have to thank Mr. and Mrs.

Geoffrey Elliott, who purchased the Driver portfolio for Bermuda. This Island would not be such a wonderful place if it were not for people like them who do so much for us. Many of their contributions are made quietly and without publicity -- so when we have the chance, we do like to take the opportunity of thanking them publicly.'' The first exhibitions will concentrate on the 19th century, with 12 of the historically valuable watercolour scenes of Bermuda by Thomas Driver. The portfolio recently donated to the people of Bermuda by Mr. and Mrs. Geoffrey Elliott comprised 35 paintings.

Other items will include three watercolours of Bermuda in 1848 by Englishman Lt. Edmund Hallewell, four pen and wash views by James Green, two watercolours by Bermudian William Tucker, two very early views (1815) of Hamilton and St.

George's by Capt. John Browne, as well as several contributions from unknown artists.

Mr. Adams said: "The new wing will be of great assistance for the Archives -- we've always needed a place to display our documentary art and photographs. We have the largest collection of old photographs in Bermuda and it's wonderful to have a space where we can show them in regular exhibitions.'' A small section of the new wing is to be devoted to the work of local artists.

Bermudian Alfred Birdsey, this year's recipient of the Bermuda Arts Council Lifetime Achievement Award, will be the first artist featured.

Premier the Hon. Sir John Swan will perform Thursday's opening ceremony. His Excellency the Governor, Sir Desmond Langley and Lady Langley, the Mayor of Hamilton, the Wor. Cecil Dismont, and Mr. and Mrs. Ondaatje will also be on hand for this latest major event in the arts calendar.

MR. CHRISTOPHER ONDAATJE -- Supporting the arts in Bermuda.