Christie's auction house says it has discovered a previously unknown copy of a 510-year-old map that has been dubbed "America's birth certificate" because it is the first to use the name for the New World.

Julian Wilson, senior specialist in Christie's books department, says the 1507 two-dimensional printed globe by German cartographer Martin Waldseemueller is "the earliest piece of writing that uses the word America."

Waldseemueller decided to name the landmass after Italian explorer Amerigo Vespucci, who helped show that lands being explored by Europeans in the 15th and 16th centuries were not — as Christopher Columbus surmised — part of Asia.

Christie's said Tuesday it will sell the map in London on Dec. 13. It's estimated to fetch between 600,000 pounds ($788,000) and 900,000 pounds ($1.2 million).