Which famous author propped a pen name which is an anagram of his forenames? The proposed name was rejected by his publisher.

Charles Lutwidge Dodgson wrote "Alice's Adventures in Wonderland" and "Through the Looking Glass" as Lewis Carroll. Earlier in his career one of his choices for a pseudonym, "Edgar Cuthwellis", was rejected (it's an anagram of his first two names).

http://www.alice-in-wonderland.net/resources/background/lewis-carroll/

The author of "Alice's Adventures in Wonderland" and "Through the Looking Glass" is Lewis Carroll. This is an pseudonym; his real name was Charles Lutwidge Dodgson. Dodgson first used 'B.B.' to sign his non-professional writings, but in March 1856, when he wanted to publish his poem 'Solitude' in the magazine "The Train", Edmund Yates, a magazine editor, thought that this one was not appropriate. Then Dodgson came up with 'Dares' (from Daresbury in Cheshire, his birthplace), but that one was also rejected. Finally he invented Edgar Cuthwellis (composed from the letters of his name), Edgar U.C. Westhill (idem), Louis Carroll (he translated his name to Latin, and back: Lutwidge = Ludovic = Louis, Charles = Carolus) and Lewis Carroll (idem). Yates chose the last one.