Apple chief Tim Cook and Samsung Electronics vice chairman Choi Gee-sung met for a second time behind closed doors to put an end to their patent battle in nine countries but failed to reach agreement. A senior industry insider on Friday said Choi and Cook met in San Francisco on July 16 but parted without agreement.

The two giant firms can no longer avoid a trial in the U.S. scheduled for July 30.

The meeting was arranged at the orders of Judge Lucy Koh of the Northern District Court of California. The two CEOs will meet again in court.

Since Apple launched its first lawsuit against Samsung in April last year, the two firms have been in legal confrontation in nine countries including Korea, Germany, and the U.S. in over 30 cases. The trial starting on July 30 affects only in the U.S., but since that is the world's largest market and Apple's home turf, the outcome will have considerable ripple effects.

The two companies are neck and neck in the global smartphone market. Samsung grabbed the biggest global market share in the first quarter of this year with 30.1 percent, and Apple came second with 23.8 percent.

In the tablet PC market, Apple leads the field by a mile, with 62.8 percent in the first quarter compared to Samsung's 7.5 percent.