It means that UNESCO has identified the archive as one of only 20 items and collections among Britain's libraries, archives and museums to represent the outstanding heritage of the UK.
The move comes amid attempts to persuade the government to intervene to save the archive after the High Court ruled in December that the Barlaston collection could be sold to help plug a £134m gap in the pension fund linked to the collapse of the Wedgwood manufacturing firm.
Other items in the Memory of the World register include King Charles I's Death Warrant and the Bill of Rights.
The UNESCO listing is likely to add to the pressure on the government to intervene - the Attorney General is awaiting a case review to see whether he will win the right to appeal over the High Court ruling - especially as the museum trust is seen as the innocent victim of the legal wrangle over the pension deficit and because the money raised from its sale would cover only around 10% of the pension shortfall.
As ATG reported last month, unless Culture Minister Ed Vaizey steps in to ringfence money raised so that creditors cannot claim it, campaigners cannot launch a fund-raising appeal.
