More than 1,500 lots, comprising clothes and personal effects belonging to actress and archetypal blonde bombshell, Marilyn Monroe, will be auctioned in New York next month.

Among them are Ms Monroe's invitation to President Kennedy's birthday salute in 1962, and the rhinestone encrusted dress in which she sang Happy Birthday at Madison Square Garden, the event that more than any other secured her place in the American pantheon.

The dress, which Ms Monroe had made specially for the event but never wore again, is expected to fetch a six-figure sum.

She bequeathed her possessions to her acting coach and mentor, Lee Strasberg, who in turn left them to his wife, Anna. A Christie's spokeswoman said she had decided to sell the collection as "we are reaching the end of Marilyn's century".