(Corrects to delete references to "10 percent" cut as NDRC did not spell out size of reduction)
* Move is the first of two planned changes to reform power mkt
* Comes amid concerns about slower economic growth
BEIJING, April 19 (Reuters) - China's state planner said on Thursday it has cut commercial and industrial electricity prices from April 1 to lower companies' costs, as Beijing aims to make the nation's energy market more efficient.
The move is the first of two changes planned as part of government reform of the country's vast power market. It also comes amid growing concerns about slower growth in the world's No. 2 economy.
The government is focusing on cutting costs of transmitting and distributing power to big end-users like shopping malls and industrial parks, as well as making the power market more transparent, the National Development & Reform Commission (NDRC) said in a statement.
It did not specify how much power prices were cut in percentage terms.
Shopping malls and industrial complexes must not charge their tenants electricity fees higher than the government's rates, it said.
The NDRC said it also wants to give access to new power distribution markets to new players in addition to the State Grid Corp of China. (Reporting by Josephine Mason and Aizhu Chen; Editing by Sam Holmes)