SINGAPORE, April 5 (Reuters) - German chemicals giant BASF said on Friday it had agreed to buy natural gas from Chinese gas company ENN Energy Holdings under a 15-year supply contract.

ENN will supply the fuel to BASF's integrated chemicals complex in Zhanjiang in Guangdong province, BASF said in a brief statement posted on its WeChat platform, without specifying the volume of the deal.

Under the agreement, ENN will invest and build a gas pipeline to supply the BASF plant.

"Natural gas is a key fuel and feedstock for both the construction and operation stage of the Zhanjiang base," Marko Murtonen, general manager of the Guangdong venture was cited as saying.

The 10-billion-euro ($10.8 billion) chemical complex, BASF's third-largest globally once complete, is due to be fully operational by 2030.

($1 = 0.9228 euros) (Reporting by Chen Aizhu Editing by Mark Potter)