The Super Puma helicopter fleet, more than half of the aircraft serving the North Sea oil industry, will remain grounded until the safety of each model can be demonstrated.

The move follows Friday's crash off Shetland that killed four oil industry workers.

Eighty representatives of oil and gas operators and major contractors attended an emergency meeting organised by Oil & Gas UK in Aberdeen yesterday to discuss the operational impact of the temporary suspension of Super Pumas helicopters.

The industry body's chief executive, Malcolm Webb, said: "The industry met to set in train appropriate actions to address the operational consequences of the current situation.

"The Super Puma fleet represents over 50% of the capacity in the North Sea. The immediate knock-on effects of this are delays and flight backlogs, with considerable inconvenience to the workforce and their families, and potential adverse effects on offshore activities. Our primary concern is assuring the safety of the workforce. The Helicopter Safety Steering Group, which met on Saturday, recommended that flights of each of the various models of Super Puma helicopter should only resume when sufficient factual information to support this decision becomes available. (Yesterday's) meeting endorsed that position."

He said further meetings of this group and other associated task groups will take place over the coming days and weeks.

Duncan Trapp, vice president for safety and quality at CHC Helicopter, whose aircraft ditched said: "Together, the regulators, authorities, aircraft manufacturer, CHC and other experts will painstakingly investigate the incident to determine - and learn the lessons of - what went wrong.

Meanwhile, oil firm Total confirmed it has chartered four vessels to pick up offshore workers due to return home from platforms in the North Sea.

One of the vessels, the Loke Viking, set off for rigs in the Lerwick area yesterday and was expected to reach the area today at a cost of £48,000 a day.