A federal judge in the heart of Silicon Valley said Monday that Google and Oracle have failed to settle a patent dispute out of court and that the case will head to civil trial.

The suit is on track to start on April 16.

"We are referred to as trial courts because, in the end, some cases just need to be tried," US Magistrate Judge Paul Grewal in the Northern California city of San Jose wrote in an order.

"Despite their diligent efforts and those of their able counsel, the parties have reached an irreconcilable impasse in their settlement discussions."

Oracle last week spurned a proposal that Google pay about $3 million in damages and potentially cut the company in for less than a percent of Android revenue.

Northern California-based business software titan Oracle rejected the offer as too low.

Oracle is accusing Google's Android software of infringing on Java computer programming language patents held by Oracle stemming from its recent purchase of Java inventor Sun Microsystems.

Google has denied the patent infringement claims and said it believes mobile phone makers and other users of its open-source Android operating system are entitled to use the Java technology in dispute.

Google has maintained that Sun, before it was acquired by Oracle, had declared that Java would be open-source, allowing any software developer to use it, and released some of its source code in 2006 and 2007.

Oracle completed its acquisition of Sun, a one-time Silicon Valley star, in January of 2010 and subsequently filed suit against Google.

Google-backed Android software is used in an array of devices that have been gaining ground in the hotly competitive global smartphone and tablet markets.