Indonesia halts search for missing AirAsia plane as night falls

* Pilot sought to change course, no distress signal sent

* Search resumes at first light, Indonesia leads probe

* "My worst nightmare", AirAsia Malaysia chief says

* Australia, India, US, offer experts, search support

* AirAsia group has never had a crash (Recasts, changes byline, adds new details throughout)

By Eveline Danubrata and Michael Taylor

JAKARTA, Dec 28 (Reuters) - Indonesia called off until first light a search for an AirAsia plane carrying 162 people from Indonesia's Surabaya to Singapore, which went missing on Sunday just after pilots requested a change in course to avoid bad weather.

There was no distress call issued by Flight QZ8501, operated by Indonesian AirAsia, 49 percent owned by Malaysia-based budget carrier AirAsia, which has had no crashes since it started flying in 2002.

Singapore said it would send two planes to join the search for the missing Airbus A320-200 early on Monday, while the United States, Malaysia, Britain, South Korea, Australia and India offered help, from planes and navy boats to experts and investigators.

"We are deeply shocked and saddened by this incident," said Sunu Widyatmoko, CEO of AirAsia Indonesia. "We are cooperating with the relevant authorities to the fullest extent to determine the cause of this incident."

On board were 155 Indonesians, three South Koreans and one each from Singapore, Malaysia and Britain, plus a French pilot.

The pilot "was requesting deviation due to en-route weather before communication with the aircraft was lost", the airline said.

The pilots were experienced and the plane last underwent maintenance in mid-November, it said. The aircraft had accumulated about 23,000 flight hours in some 13,600 flights, according to Airbus.

QZ8501 fell out of contact with Jakarta air traffic control at 6:17 a.m. (2317 GMT Saturday). It was roughly halfway between Surabaya and Singapore when it went missing in bad weather, somewhere from Tanjung Pandan on Indonesia's Belitung island to Pontianak, in West Kalimantan, Borneo.

Malaysia AirAsia chief Tony Fernandes went to Surabaya to update dozens of relatives of passengers who waited anxiously. The carrier swapped its distinctive bright red logo for a grey background on its website and social media accounts.

"This is my worst nightmare," Fernandes said on Twitter. "But there's no stopping", he said of the search.

The incident caps a disastrous year for Malaysia-affiliated airlines. Malaysian Airlines Flight MH370 went missing on March 8 on a trip from Kuala Lumpur to Beijing with 239 passengers and crew on board and has not been found.