By Laurence Frost

PARIS (Reuters) - Aston Martin Chief Executive Andy Palmer warned on Friday that Britain's exit from the European Union was likely to require additional "productivity and efficiency" gains at the British sportscar maker,

Palmer urged the UK government to secure tariff-free access to EU markets.

"We acknowledge the decision and the rule of democracy," Palmer said in a statement to Reuters after Britain's referendum vote to leave the European Union.

"Aston Martin will now orientate its business to deliver our mid-term plan in the context of the exit and the market volatility that may exist during the period of transition," Palmer said, adding that a weaker pound should "partially offset" the increased instability.

"As the UK could now be subject to new trade tariff barriers, we also anticipate the need for additional productivity and efficiency in the medium term," he said.

The government must now "maintain economic stability and secure a deal with the EU which safeguards UK automotive interests - this includes securing tariff-free access to European and other global markets."

(Reporting by Laurence Frost; Editing by Richard Lough)