The writer Benjamin Moser signed an agreement this week to write the authorized biography of Susan Sontag, the legendary novelist, essayist and critic who died in 2004 at 71.
Ms. Sontag’s son, the writer David Rieff, and the literary agent Andrew Wylie approached Mr. Moser about the project. Mr. Moser’s biography of the Brazilian writer Clarice Lispector, “Why This World,†was a finalist for a National Book Critics Circle award in 2009.
Mr. Moser, who grew up in Texas and now lives in the Netherlands, said in an inteview via e-mail that he expected the book to take at least three to four years to complete.
“It’s only since I’ve started reading her from A to Z that I realize how much she wrote and did,†Mr. Moser said. “How everywhere she was. It’s hard to think of a writer’s life that ranged as widely.â€