BEIJING, Sept 27 (Reuters) - China has ditched blanket production cuts on heavy industry in its finalised winter anti-pollution plan, allowing local authorities to adopt measures based on regional emission levels.

The plan, issued by the Ministry of Environment and Ecology (MEE) on Thursday, is the latest sign of Beijing fine-tuning its policy in a years-long fight against smog. Earlier this month Reuters reported that China was considering such a move for its northern provinces.

Before the revision, in an earlier draft of its winter anti-pollution campaign, the MEE had still been planning blanket production cuts of 30-50 percent on heavy industry in 28 northern cities.

“Local authorities should carry out production cuts based on their individual situation and refrain from adopting blanket cuts,” the MEE said, however, in the finalised plan.

Local governments can also shorten or extend the timeframe of production restrictions based on their monthly air quality, the ministry said.

Production cuts for last winter started from mid-November 2017 and lasted until mid-March of this year.

Heavy industry, including steelmaking, cement factories, coke plants, metal casting and chemical production, will be the main targets of any restrictions, but output cuts for individual companies will be based on their emissions record.

Steel mills with blast furnaces, coke plants, and primary aluminium and alumina producers able to meet ultra-low emission standards will be exempt from winter output cuts.

Steelmakers that use electric-arc furnaces and mini-mills that only use scrap steel as raw material will also be pardoned from output limits.

Provincial authorities will be given until end-October to submit their own production cutting plans to the central government. No changes will be allowed afterwards, the MEE said.

The ministry also said it will continue its clean-heating project by replacing coal-fired systems with gas or electrical systems in an additional 3.62 million households in 28 northern Chinese cities. Last year, China converted the heating systems in 3.94 million households in the same cities.

The MEE aims over the coming winter to reduce average PM2.5 concentration by around 3 percent from levels recorded in the same period last year. The reduction target has been revised lowered from 5 percent in the earlier draft. (Reporting by Muyu Xu and Dominique Patton; Editing by Tom Hogue)