NEW YORK - Tina Fey, already the busiest of stars thanks to her Emmy-winning role in "30 Rock" and definitive impersonation of Republican vice presidential candidate Sarah Palin, is working on a book.

According to two publishing officials with knowledge of the negotiations, Little, Brown and Company will release a book of humorous essays by the 38-year-old Fey. Her many writing credits include "30 Rock" and "Saturday Night Live," and the feature film "Mean Girls."

The officials asked not to be identified, citing the confidentiality of negotiations, and declined to give financial details Friday. Little, Brown spokeswoman Heather Rizzo did not immediately respond to a request for comment.

The deal was first reported Friday by The New York Observer.