FILE PHOTO: A Nissan logo is seen at a car dealership in Ciudad Juarez, Mexico May 30, 2017. REUTERS/Jose Luis Gonzalez

LONDON (Reuters) - Japanese carmaker Nissan 7201.T, which operates Britain's biggest car factory, has delayed the start of pay talks with its staff in the country until the terms of Brexit become clearer.

London and Brussels hope to reach a deal by next month but automakers have triggered contingency plans for any lack of agreement including changing their shutdown periods, stockpiling parts and certifying models in the European Union.

Automakers generally sign two-year pay deals with their staff. Nissan was due to start negotiating with its workforce this autumn.

“In agreement with our employee representatives, the 2019/2020 pay negotiations in our UK plant and technical center will commence in 2019 when we have better clarity on the future business outlook,” a spokesman said.

The firm, which built nearly one in three of Britain’s 1.67 million new cars last year at its Sunderland plant, warned this month that a ‘no-deal’ Brexit would have “serious implications” for British industry.

Carmakers are worried that port and motorway hold-ups could slow the movement of components and finished models, crippling output and adding costs, if Britain fails to reach agreement with the EU over its departure from the bloc on March 29.

Nissan said in 2016 it would build two new models at its Sunderland site after what a source said was a letter from the British government promising extra support if Brexit hit the competitiveness of the factory.