Stamp dealer Stanley Gibbons has become the latest business to be enveloped in Asian market turmoil after revealing that weakness in the region could hit its high value sales.

The group issued a trading update after it had seen its shares plunge by more than one third since fears over a slowdown in China erupted last month.

They climbed five per cent in the latest session after Gibbons reassured investors that it was still on course to achieve market expectations for annual results for the year to the end of March.

The firm, which trades in a range of collectibles including stamps, coins, medals, banknotes and books, said it was "currently working on a number of high value sales with potential new clients" which could have an impact on first half trading.

It said: "Given weakness in particular in our Asian operations during the first half, it is currently uncertain whether high value sales completed by September 30 will be at the level required to achieve the group's internal budgets for the first half."

The group said however that "detailed dialogue is ongoing with a number of interested parties".

Gibbons added that its auction calendar for this year was more heavily weighted towards the second half than last year meaning it was "budgeted to deliver materially higher revenues and profits" in that period.

The firm also said that, after a 22 per cent rise in online revenues for the year to March, double digit growth in this area had continued in the financial year to date.

However it said its new Marketplace, allowing customers to buy from it and trusted sellers, had "yet to make a material contribution to this growth" following its launch in May and for now it was holding off from marketing investment to boost these sales.

Gibbons, founded in 1856, has its main outlet on London's Strand.