Three maps dating from the 16th and early 17th centuries have been taken. Similar thefts have been discovered at a host of institutions in America, including public libraries in New York and Boston, and Yale University library.
The FBI has requested that all institutions holding rare maps review their collections as soon as possible.
Two of the three maps missing from the British Library, from which no books or manuscripts are allowed to be removed, were of North America - a subject area of particular interest and value to collectors. An untitled oval map was cut from A True Discourse of the Late Voyages ... of Martin Frobisher by G Best dating from 1578. Sir Martin Frobisher was an English mariner whose expeditions to the New World included the first attempt by an Englishman to find the Northwest Passage.
Another untitled map of New England and Canada was taken from An Encouragement to Colonies, a book written by a Scottish nobleman, Sir William Alexander, in 1624 to invite adventurers to colonise Nova Scotia, which he had been given by James VI. The third was a world map dating from 1520 by Peter Apian, a German mathematician and cartographer, cut from the book Ioannis Camertis Minoritani. They are likely to be worth tens of thousands of pounds.
Jonathan Potter, one of London's leading dealers, said: "They have been targeted by somebody who is aware of their rarity and aware of the demand for them. There are other equally rare maps [in the British Library] but in less interesting areas. It's not random at all." The maps were taken in March and June but details are only now being made public.
Mr Potter said it was very difficult for traders to identify stolen maps unless they were alerted to thefts - and sometimes the institutions themselves were unaware that items were missing. They were not so rare as to be obviously suspicious without a warning. "The British Library did alert the trade, though a little bit later than the trade would have liked," Mr Potter said.
The Metropolitan Police would not discuss the British Library thefts because investigations were continuing. But a spokeswoman said of the thefts from Yale: "We are working closely with the Americans to assist their investigation and recover stolen maps that are currently located in the UK."
The British Library houses more than four million maps, dating from the 10th century - the second largest map collection in the world. As well as printed maps the library also holds large numbers of hand-drawn, manuscript maps. Rare maps of North America are a feature of the collection.
Potential weaknesses in the library's security system were highlighted in 1996, when Melvin Perry, 49, a petty thief from Essex who became one of Europe's foremost map thieves, was convicted of stealing coloured plates from texts. The conviction prompted experts to raise concerns about funding for the security of European libraries.
Last year Peter Bellwood, a gambling addict with debts, was jailed for four and a half years for stealing at least 50 rare maps from the National Library of Wales in Aberystwyth and selling them for £70,000. Last month, a US dealer, Forbes Smiley, 49, was arrested at Yale University and charged with stealing maps worth more than $300,000 (£165,0000).Reuse content