An antiques dealer who tried to sell a rare copy of Shakespeare's First Folio has been found guilty of handling stolen goods and removing stolen property from the UK.

But a jury at Newcastle crown court cleared Raymond Scott, 53, of stealing the book, which has been described as part of England's cultural legacy.

The £15m copy of the 1623 compendium of Shakespeare's plays went missing from Durham University in 1998 along with early handwritten manuscripts bearing an English translation of the New Testament and a fragment of a poem by Chaucer.

They were in a public display charting the progress of English literature from the Middle Ages to the 20th century.

Interpol had been watching for the reappearance of the book but the trail remained cold until Scott walked into the Folger Shakespeare library in Washington DC – one of the world's leading centres of Shakespeare studies – and asked staff to verify the First Folio as genuine. He claimed to have bought the collection of 36 plays in Cuba.

Scott was remanded in custody by Judge Richard Lowden, who told himhe faced a substantial jail sentence. The case was adjourned to a date to be fixed to allow a psychiatric report to be prepared.