Korean Air has been banned from opening new international routes after the latest in a growing list of serious accidents saw one of its cargo jets crash near Stansted Airport.

The action by South Korea's Ministry of Construction and Transportation highlights the growing concern over the country's national airline, which has one of the worst safety records in the aviation world.

It is estimated that more than 700 people have died in the past 20 years in crashes involving its planes.

In 1997 a Korean Air jumbo jet crashed on the Pacific island of Guam, killing more than 200 people.

In April this year, one of its MD-11s crashed and exploded shortly after take-off from Shanghai airport, killing all three crew members and four residents.

That month South Korea's President, Kim Dae-jung, told the company it had to change its management, and said it put growth and profits ahead of safety.

The following week, the founder and head of Korean Air, Cho Yang-Ho, stepped down saying he was taking responsibility for the a number of recent air accidents involving the airline.

'Amateurish and unprofessional'

Korean Air has grown rapidly in the last 40 years, mirroring the rapid economic development of South Korea.

It now carries cargo to 32 cities in 21 countries.

But Korean Air, like many big Korean companies, has been dominated by the patriarch's family.

Critics say that means the management can be amateurish and unprofessional, as people in senior positions are too often chosen not for their qualifications and experience, but because they have the right connections.

Recently an internal report leaked onto the internet alleged that an authoritarian cockpit culture, inadequate English and pilot error were compromising safety.

One of the concerns is that civilian and former military pilots working for the airline do not gell together.

Chris Hodgkinson, technical director of the Guild of Air Pilots, told BBC Radio 4's Today programme that a mix of pilots would not normally be a concern, unless the set-up in the cockpit was too autocratic.

He said: "There's no harm in having ex-military pilots with civil trained pilots, assuming you have the right culture in the airline, and indeed they have quite a lot of expatriate pilots, mainly Americans as I understand it, who fly with them."

Mr Hodgkinson said outside contractors were helping Korean Air with their training in a bid to change the culture of the airline.

"But maybe it hasn't started to work yet", he added.

After the Shanghai crash, the US Department of Defense advised its staff not to use Korean Air for official travel.

Korean Air's partners, Air Canada, Air France and Delta Airlines, suspended their agreements to share flights and reservations with the airline.

Expert help invited

Korean Air, under its new head, Yi Taek-shim, has promised to become one of the world's safest airlines.

In June it announced plans to invite foreign experts to train pilots and oversee safety, saying it wanted to develop a "Western-style cockpit culture".

Korean Air employs few foreign pilots. Many of its cockpit staff learned to fly in the military during national service - critics say that is the wrong sort of background for civil pilots.

BBC correspondent Andrew Wood says that recently the airline has ploughed £120m into retraining its pilots, but that the results of that investment were still unclear.