It was a chance meeting in the humdrum lobby of an anonymous Dutch hotel.

But the fortunate conversation between a curator from Scotland and one of America's leading collectors has led to one of the most significant loans to Scotland's national collection in recent history.

An exhibition of masterpieces from a significant private collection, to open at the Scottish National Gallery next month, would not have happened if Tico Seifert, a senior curator at the National Galleries of Scotland, and an American lawyer and collector, Asbjörn Lunde, had not got talking at that hotel in Maastricht, the Netherlands four years ago.

Lunde and Seifert soon started talking about the American's extensive private collection of 19th century Norwegian and Swiss landscape painting, which features works by Caspar Wolf, Robert Zünd and Giuseppe Camino.

Lunde invited Seifert and also Michael Clarke, director of the National Gallery of Scotland, to his house in upstate New York to view his collection - and soon a deal was made: the National Galleries of Scotland will have access to his treasure trover of art for the next two years.

The first result of these is Rocks and Rivers, Masterpieces of Landscape Painting from the Lunde Collection which opens on April 3.

"The beginning of it was also so coincidental, " Seifert said, "We were introduced in some hotel in Maastricht and we got talking - he is such a kind person, a gentleman and he simply said: 'Why don't you come to New York and have a look at my collection.'

"It grew from there. It is a very fine collection indeed.

"It is a multi-year arrangement and are taking thirteen paintings on loan, I had access to the whole collection and he was very open to us using everything he has."

All the works are being shown in Scotland for the first time, and display a fairly unknown chapter in 19th-century landscape painting, with expansive views and nature studies of locations in Scandinavia, Italy and Britain, as well as renowned sites in the Alps, such as Lake Lucerne and the Bernese Oberland.

Lunde is the son of Norwegian émigrés to the United States, and he began collecting in 1968.

The first works he acquired were by Thomas Fearnley and fellow Norwegian Knud Baade.

Now one of the world's leading experts and collectors in this area, Lunde has since lent and gifted works to prestigious cultural institutions, including the Metropolitan Museum (New York), the Sterling and Francine Clark Art Institute (Williamstown, MA), and The National Gallery of Australia (Canberra).

The National Galleries of Scotland say works by these masters are "extremely rare" in British public collections, and, for the duration of the loan, the Scottish National Gallery is set to be the only gallery in the UK where visitors can explore such a variety of their paintings.

Prominent Norwegian landscape painters include Dahl (1788-1857) and Fearnley (1802-1842).

Fearnley is regarded as Dahl's outstanding pupil.

He travelled widely, and in 1836-38 visited England, from where his grandfather had emigrated to Norway.

Fearnley's Fisherman at Derwentwater (1837) is a depiction of the Lake District.

Alexandre Calame (1810-1864) created views of expansive mountains, dense forests and rushing torrents, which are indebted to the work of 17th-century Dutch landscape artists such as Jacob van Ruisdael.

Exhibited is Calame's A View of the Jungfrau Massif seen from above Interlaken, of about 1854-60.

Michael Clarke, director of the Scottish National Gallery, said: "It is a privilege and a pleasure for the Scottish National Gallery to show these outstanding paintings from the Lunde Collection.

"We are delighted to present to our audiences the stunning works of these landscape masters, highlighting an important yet little-known chapter in nineteenth-century landscape painting."