BERLIN (Reuters) - Luxury carmaker Porsche expects the transition to electric vehicles to take longer than it thought, it said on Monday, having previously said its aim was for 80% of sales to be all-electric by 2030.

It has now watered down that goal by tying it explicitly to customer demand and developments in the electromobility sector, saying in a statement only that it could now deliver on the 80% target if those factors warrant it.

"The transition to electric cars is taking longer than we thought five years ago," Porsche said in a statement.

"Our product strategy is set up such that we could deliver over 80% of our vehicles as all electric in 2030 - dependent on customer demand and the development of electromobility."

Executives at carmakers from Mercedes-Benz to Renault have warned in recent months that goals they set in recent years for fully electric sales in the next decade were too ambitious as customers remained reticent to make the switch away from gas-powered cars.

Porsche, struggling with low EV sales this year so far, highlighted the disparity in its three key markets in EV uptake, with demand far ahead in China, slower in Europe and spotty in the U.S.

"Our double strategy is more important than ever," Porsche said, referring to its continued development of both combustion engine and electrified cars.