Jury selection began today in a high-stakes US patent battle between Apple Inc and Samsung, the culmination of more than a year of pre-trial jousting with billions of dollars in the balance.

Apple and Samsung, the world's largest consumer electronics corporations, are waging legal war around the world, accusing each other of patent violations as they vie for supremacy in a fast-growing market for mobile devices.

The fight began last year when Apple sued Samsung in a San Jose, California, federal court, accusing the South Korean company of slavishly copying the iPhone and iPad.

Samsung countersued.

The stakes are high, with Samsung facing potential US sales bans of its Galaxy smartphones and tablet computers, and Apple in a pivotal test of its worldwide patent litigation strategy.

Long lines outside the federal courthouse in San Jose marked the beginning of the trial as lawyers, media and observers flooded the building to watch the proceedings.

A 10-member jury will hear evidence over at least four weeks, and it must reach a unanimous decision for Apple or Samsung to prevail on any of their claims.

That the jurors will hail from Silicon Valley, where Apple is an icon and major employer, will be something for Samsung to consider during the jury selection, said James Dobson, a jury consultant with Empirical Creative.

"Although certainly if I were Samsung, I would be concerned about what prospective jurors think about Apple, given that it's a huge employer there," Mr Dobson said, "by and large jurors want to do the right thing and decide the case on the merits."

It has been tough going so far for Samsung in the case.

US district judge Lucy Koh halted US sales of the Galaxy Tab 10.1, giving Apple a significant early win.

This was followed by a pretrial ban on the Galaxy Nexus phone. Samsung has appealed both orders.

The trial is expected to last at least four weeks.

Reuters