Legal Question in Intellectual Property in New York

Re: short story co writer entitld to Novel rights?

If there's no written agreement between the co-writer and you the copyright is deemed split equally and either one of you may license rights in the original story (including to yourself) on a non-exclusive basis. You each owe accountings and payments to the other should such non-exclusive licenses generate revenues. The problem for you is that to write a novel and publish, you'll probably need to grant exclusive rights and that, in the absence of an agreement, is going to be a problem for you. Unless you figure out a way to talk to your co-writer and work out some arrangement, you may have to consider writing a different novel. Even if you make substantiial changes and lengthen the work, the novel will be, in part, a derivative work of the story and that is a right under copyright.

Re: short story co writer entitld to Novel rights?

Any work based on the original work is considered derivative. Only the holder of the copyright on the original form can produce or permit someone else to produce a derivative work. Consequently, you as a co-holder of the copyright on the original work can expand, change, or further develop it. However, your co-author and co-holder of copyright retains his/her rights in the derivative work to the same extent as he/she had in the original and must be credited accordingly. You should consult with an attorney to explore your rights and obligations concerning the work you created with the other person, especially if you intend to exploit (i.e. make some money from) the short story and any derivative works.