BERLIN, Nov 16 (Reuters) - Germany's VCI chemical industry association on Tuesday again raised its price and revenue guidance for 2021 even as growth began to show signs of a slowdown in the third quarter.

The association expects prices to rise by 8.5% by the end of 2021, up 2 percentage points from its August forecast.

Similarly, revenue is now seen as rising by 15.5%, versus the 11% previously predicted.

The association reaffirmed its full-year chemical production outlook of a 4.5% growth.

Strong demand for vaccines, an ongoing rise in chemical prices and more orders from industrial customers, especially abroad, helped the industry post a higher outlook, it said.

However, high energy costs and supply bottlenecks would continue to slow business in the coming months, said VCI.

"Neither the materials shortage or high energy costs are expected to improve anytime soon. These factors are weighing on the economy and will cause the chemical business to cool down further in the coming winter," said VCI head Christian Kullmann said in a statement.

Germany is Europe's largest chemical producing nation.

(Reporting by Miranda Murray, editing by Emma Thomasson)