A picture believed to be the earliest known work of British artist LS Lowry is being displayed and sold at a fine arts fair at the NEC in Birmingham.

The small drawing, which measures two-and-a-half inches by just over four inches, is a pencil and watercolour sketch of yachts sailing on the sea.

The artist, from Salford, Greater Manchester, is believed to have drawn the coastal scene in 1902 at the age of 15.

The signed work, priced at £50,000, is being exhibited at The 5th National Fine Art and Antiques Fair, held at the NEC from today to 20.

Event organiser Duncan Phillips described the picture as a "unique work of art" and said there had been a great deal of interest in it. "It's very rare for specialist pictures to come on the open market and so when they do, there is always a lot of interest," he said.

"The demand for Lowry has never been greater than it is at the moment. It's at an all-time high.

"I think he has finally been recognised as Britain's most popular and interesting artist in the 20th Century."

The picture is being sold and displayed by Neptune Fine Art, which specialises in Lowry's work.

It was exhibited at the Royal Academy of Arts in London in 1976, said Mr Phillips.

Lowry, who died in 1976, is famous for painting scenes which depict life in industrial northern England.