"We're absolutely in our glide path to make the decision by the end of this year... but we cannot say when we will be able to start production in China," CEO Ralf Speth told reporters at the Frankfurt auto show on Tuesday.

He added that the timing of a production start in China depended on official approval by Chinese regulators.

JLR, a unit of Tata Motors , is best known for its range of large sport utility vehicles such as the Range Rover and high performance sports cars like the XJ.

Nonetheless, Speth said he did not expect any problems achieving the European Union's strict target for carbon dioxide emissions by 2020.

"We see absolutely no problem reaching the 95 grammes per kilometre. We want to reach that."

JLR declined to publish its current fleet emissions but it did say the company is on track to reach about 180 g/km by 2015, giving it then just five years time to reduce its fleet's carbon dioxide output by nearly 50 percent.

Speth said emissions would be cut by introducing a small 2.2 litre four cylinder diesel engine for models like its Range Rover Evoque, whose two-door version can manage less than 130 g/km.

According to the JLR chief, the two brands currently achieve almost no synergies with Tata Motors but JLR and its Indian parent were in negotiations to squeeze out a "limited" number of savings by jointly utilising motors that would be at the bottom end of the British carmaker's engine range.

Sales of Jaguar fell 8 percent in the first eight months to nearly 31,000 cars, but demand is expected to pick up with the launch of the new XK and the facelifted XF. New orders in Germany, for example, jumped 20 percent in August, according to the company.

Land Rover increased its sales by over 15 percent to close to 134,900 vehicles during the same period.

Together the two sold roughly 225,000 vehicles worldwide last year.