BEIJING (Reuters) - The Asian Development Bank [ADB.UL] (ADB) approved a third loan, worth 428 million euros ($506 million), to help improve air quality in China’s smoggiest region of Beijing-Tianjin-Hebei, it said in a statement on Thursday.

The loan aims to encourage the large-scale adoption of advanced technologies by major emitting industries including transportation, power generation, heating and fertilizer production.

Two previous loans were approved in 2015 and 2016, with a combined value of just under $800 million, aiming to strengthen policy reforms and regulatory capacity in Hebei province, and to help small and medium-sized firms scale up investments in pollution-reduction projects in the region.

Heibei, heartland of steelmaking and also home to six of China’s 10 smoggiest cities in the first nine months of this year, is on the frontline of the country’s campaign against air pollution.

It vowed to cut concentrations of hazardous airborne particles, known as PM2.5, by 25 percent by the end of this year. However, PM2.5 in the city of Handan in Hebei rose by an average of 8.8 percent in October and November, despite local authorities’ steadfast efforts to cut emissions.

“We remain committed to helping the Chinese government improve air quality and reduce pollution in the greater Beijing-Tianjin-Hebei region, where a third of the country’s economic growth comes from,” said Lin Lu, senior energy specialist at ADB’s East Asia Department.

ADB’s assistance is expected to attract around 1.3 billion euros in co-financing from public and private sectors, according to the statement.