BEIJING, April 18 (Xinhua) -- China is screening the fourth batch of pilot state-owned enterprises (SOEs) for mixed ownership reform, an official from the country's economic planner said Thursday.

"The keynote for this batch is scale and field expansion, given that the previous three batches centered merely on a few key areas and a handful of companies," according to Yuan Da, spokesperson of the National Development and Reform Commission.

Over 100 SOEs will be included in the fourth batch.

Since 2016, China has selected 50 SOEs in three batches to conduct the pilot reform in fields including power, energy, civil aviation, telecommunications and defense.

Besides SOEs in key areas, the fourth batch will include pilot companies in competitive fields that have strong demonstration significance, especially influential mixed ownership enterprises.

A shortlist of companies for the fourth batch have been submitted to the Leading Group for State-owned Enterprises Reform under the State Council, Yuan said.

Upon approval, the pilot work for the fourth batch will come into force, according to Yuan.