SUNDERLAND, England - No-deal Brexit tariffs of 10% on cars would be unsustainable for Nissan in Europe, where the carmaker's operations include a British and Spanish plant, the Japanese firm warned on Thursday.

Nissan made nearly one in three of Britain's 1.5 million cars last year at its northern English Sunderland factory, although annual production levels at the site will drop this year.

The car industry, Britain's biggest exporter of goods, is concerned that World Trade Organisation tariffs of 10% on vehicles alongside new customs checks and delays could halt production if there is a disorderly Brexit on Oct. 31.

"That will represent a significant cost increase on our vehicles that will have to face the competition in Europe and they won't be affordable," the firm's European Chairman Gianluca de Ficchy told reporters.

"If there will be a no-deal and a no-deal will be associated with WTO tariffs application, that won't be sustainable for us," he added.

Prime Minister Boris Johnson has said he is prepared to take Britain out of the European Union without an agreement but is seeking a deal with the bloc, although time is running out to secure an orderly departure before the deadline in three weeks.

Nissan said it was examining a host of scenarios and wants the tariffs not to be applied if Britain leaves the bloc without an agreement.

"We are asking not to have tariffs being applied in a no-deal scenario because otherwise the tariffs won't be sustainable for us," de Ficchy said.

(Reporting by Costas Pitas, Editing by Paul Sandle) ((paul.sandle@thomsonreuters.com; +44 20 7542 6843; Reuters Messaging: paul.sandle.thomsonreuters.com@reuters.net))