* UAE, Saudi Arabia are vital trade routes for Qatar
* With those blocked, Oman has made its ports available
* Food importer says hundreds of containers on their way (Updates with further comment, detail, context)
DOHA/LONDON, June 12 (Reuters) - Qatar and container lines have launched new shipping services via Oman in an effort to sidestep a port ban in neighbouring countries and secure a food lifeline after other Gulf states severed ties with Doha last week.
Saudi Arabia, the United Arab Emirates and some other Arab countries cut diplomatic, travel and trade ties with Qatar last week, accusing it of supporting Iran and funding Islamist groups, accusations Doha denies.
The severing of air, sea and land transport links has closed crucial import routes for Qatar and its population of around 2.7 million people who are dependent on imports for most of their food needs.
China's COSCO Shipping Lines Co Ltd, Taiwan's Evergreen and Hong Kong Kong's OOCL have suspended container services to and from Qatar.
Qatar Ports Management Company (Mwani) announced on Sunday two new shipping services will each run three times a week between Qatar's Hamad Port and the Omani ports of Sohar in the north and Salalah in the south.
Oman is a member of the Gulf Cooperation Council but takes a relatively independent diplomatic approach to the other five states in the bloc, particularly over Iran, the non-Arab, Shi'ite Muslim state across the Gulf.
"It is impossible to confidently predict how the situation will develop, for how long the 'Qatar ban' will remain in place and whether any further restrictions will be implemented," said Rania Tadros, managing partner with law firm Ince & Co Dubai.
Larger container ships are unable to dock at ports in Qatar due in part to shallow waters, so shipping lines use feeder services, which transport containers from the larger regional port of Jebel Ali in the UAE.
Thousands of containers destined for Qatar are still stuck at Jebel Ali, according to Qatari importers.
A Qatari food company owner said shipments began arriving on Sunday from Oman, and that some 12 vessels were headed to Qatar from Sohar and Salalah.
"There are around 300 containers of fresh and frozen food coming. Some have arrived and the others are on their way," Ahmed al-Khalaf said.
He said containers at Jebel Ali were still stuck, but that others, including from Europe, were being diverted to Oman's ports.
The world's no. 1 container line, Maersk of Denmark, said on Monday it would accept new bookings for container shipments to Qatar from Oman.
Swiss-based MSC, the world's no. 2 line, said it would deploy a new dedicated shipping service to Qatar from Salalah.
"Suppliers are working on trying to route shipments through Oman. There is still a question over whether there will be diplomatic pressure brought to bear on Oman and what impact that could have on this latest effort," a shipping source said.
Iran and Turkey have already flown in food supplies to Qatar as the gas-rich country seeks other sources. (Editing by Sami Aboudi and Robin Pomeroy)