Chinese rocket launcher are unable to determine who's to blame for a January explosion that destroyed a $160-million satellite, Bloomberg Business News reported yesterday.

Bermuda-based satellite insurer, ACE Ltd., was involved in the insurance programme for the satellite, with an undisclosed percentage of the cover.

A six-month joint investigation into the failed Apstar-2 launch concluded that a winter wind shear damaged either the satellite or the rocket it was being launched on, causing both to explode.

"The explosion happened in an instant, so the technicians on both sides had no way to pin down the exact cause,'' said Ma Qimin, an official with China Great Wall Industry Corp., the Chinese company that launched the satellite.

"Experts from both companies are working to ensure a successful launch next time,'' said Ma, director of China Great Wall's launch services.

Hong Kong-based Asia Satellite Telecommunications Co., said the launch of its AsiaSat 2 has been put back a third time, to September at the earliest. It said Great Wall's work to reinforce the rocket fairing, which encases the satellite, could delay the launch further.

"We are happy they have identified two possible causes so we can handle the problem,'' said Winnie Pang, AsiaSat's corporate affairs manager.

The Apstar-2 communications satellite exploded 50 seconds after launch from the Xichang rocket base in southwest China on Jan. 26. It was still connected to a Long March 2E rocket built by China Great Wall.

China initially blamed the satellite design by Hughes for the failure. Hughes is a subsidiary of automaker General Motors Corp.