Jurors this week ruled that Google's Android operating system for smartphones violated Java software copyrights but deadlocked when it came to the pivotal question of whether it constituted "fair use" that made it acceptable.

If Google's use of copyrighted Java application programming interfaces (APIs) in Android was fair use, Oracle would deserve no damages from the Mountain View, California-based Internet firm under the law.

Google late Tuesday filed a motion asking US District Court Judge William Alsup to declare a mistrial in the copyright phase of the trial and have both questions presented to a new jury in a retrial.