Publishers fear the next edition will never appear in print form because its vast size means only an online version will be feasible, and affordable, for scholars.
Its all academic for now anyway, they say, because the third edition of the famous dictionary, estimated to fill 40 volumes, is running at least 20 years behind schedule.
Michael Proffitt, the OEDs first new chief editor for 20 years, said the mammoth masterpiece is facing delays because information overload from the internet is slowing his compilers.
His team of 70 philologists, including lexicographers, etymologists and pronunciation experts, has been working on the latest version, known as OED3, for the past 20 years.