China has set a deadline of 2019 to impose tough new sales targets for electric plug-in and hybrid vehicles, slightly relaxing an earlier plan to launch the rules from next year that had left global automakers worried about being able to comply.

Carmakers will need to amass credits for so-called new-energy vehicles (NEVs) equivalent to 10 percent of annual sales by 2019, China's industry ministry said in a statement on Thursday. That level would rise to 12 percent for 2020.

A single vehicle can generate multiple credits meaning the proportion by NEVs by volume would likely be lower.