* Oct coal imports overall jump 55 pct to 21.58 mln tonnes
* Mongolia imports rocket 221 pct from year ago
* 'Domestic supply still smaller than expected' -analyst (Adds detail from data and analyst comment)
BEIJING, Nov 25 (Reuters) - China's imports of coal from Mongolia more than tripled in October from the same month a year before, customs data showed, reflecting tight supply in the domestic market that stoked much bigger shipments from foreign producers to meet demand.
Output from domestic miners has been shrinking as a result of China's campaign to cut back overcapacity in its coal industry. That helped overall coal imports last month climb 55 percent to 21.58 million tonnes - a number likely to add urgency to a new push by Beijing calling on miners to raise output.
Imports from Mongolia - mainly coking coal, used in steel-making - stood out among the October numbers, rocketing 221 percent to 2.31 million tonnes. October's data brought year-to-date imports overall to 201 million tonnes, 18 percent more than a year ago.
"Domestic supply is still smaller than expected, as coal miners have strong concern of production safety and are reluctant to expand output," said Zhang Min, coal analyst at Sublime China Information Group.
The tightness of domestic supply has sent prices much higher this year. Coking coal prices at Dalian Commodity Exchange DJMcv1 have surged 185 percent since the beginning of 2016.
A key part of China's drive to upgrade the domestic coal industry is conducting safety inspections at mines through to the end of year.
"It takes time for coal miners to lift output. The domestic market is expected to be short in supply until January," said analyst Zhang.
Shipments from Australia increased 32.2 percent in October from a year earlier to 5.4 million tonnes, while imports from Indonesia jumped 57.9 percent at 3.25 million tonnes, customs data also showed on Friday.
Imports from North Korea rose 38.8 percent to 1.82 million tonnes, according to the data.