The 37-year-old 'Inception' star - who has previously dated Blake Lively and a string of models including Gisele Bundchen and Bar Refaeli - ended things with the 23-year-old supermodel last month after almost a year together because she wanted to get serious.
A source told the New York Post's Page Six: ''Erin wanted things to get more serious between them, but Leo is not ready to settle down.
''While it would seem amazing that he wouldn't want to settle down with one of the world's most beautiful women, Leo leads a charmed life.''
Friends of the actor, who is currently filming 'The Wolf of Wall Street' with martin scorcese, are said to be shocked by the break-up as they thought Erin was ''the one'' for Leonardo.
An insider said: ''A few months back it seemed like he was really into Erin. She's smart, beautiful and, importantly, got on with his mum.
''They are still friends. The timing just wasn't right for them. They still care about each other and remain friends. ''
Leonardo recently admitted that he hasn't met the love of his life yet and was already spotted flirting with a group of models at a Halloween party in New York's Standard hotel last month (27.10.12) shortly after their split.