In Marvel's early "Journey Into Mystery" comics featuring "the Mighty Thor", 'Jane Foster' was an office nurse who became the Norse god Thor's first love, via his human identity 'Dr. Don Blake'.
Portman will star opposite actor Chris "Star Trek" Hemsworth as 'Thor' and Tom Hiddleston as the god of mischief 'Loki' for director Kenneth Branagh and Marvel Studios producer Kevin Feige.
Marvel will self-finance "Thor" with a $500 million credit facility through Merrill Lynch, as they did with "Iron Man" and "The Incredible Hulk".
Principal photography is prepping for an early 2010 start.
The film will be distributed by Paramount, May 20, 2011.
"Thor" is one of a slate of films produced by Marvel Studios based on Marvel comic book characters, including "Iron Man 2" set for a May 7, 2010 release, "The First Avenger: Captain America", set for July 22, 2011 and "The Avengers" on May 4, 2012.