Samsung had signed an agreement with Qualcomm not to sue the chipmaker or its customers for using Samsung's 3G patents, but this agreement was called off when Apple took Samsung to court over the Galaxy Tab, Samsung admitted in the Australian Federal Court this morning.

The Federal Court today commenced the long-awaited case between Apple and Samsung over alleged patent infringements by the two companies. The court began hearing Samsung's counterclaim against Apple -- that the company infringed on three standards-essential 3G patents held by Samsung in the iPhone 4, iPhone 4S and iPad 2.

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