UPDATE 1-China's June unwrought copper imports rise to record 656,483 tonnes

* Imports helped by arbitrage window, improved demand -analyst

* June aluminium exports down by a third (Updates with details, background, analyst comment)

BEIJING/SHANGHAI, July 14 (Reuters) - China’s unwrought copper imports climbed 50% in June from the previous month, customs data showed on Tuesday, buoyed by cheaper prices of overseas metal, increased manufacturing activity and scrap shortages.

Imports by the world’s top copper consumer were 656,483 tonnes last month, the General Administration of Customs said, the highest figure ever published for a single month according to Reuters calculations. The customs department typically publishes a joint number for the first two months of the year.

June’s number was up from 436,030.6 tonnes in May, and double the 326,000 tonnes imported in June 2019.

In the first half of 2020, imports totalled 2.84 million tonnes, up 25% year-on-year, customs said.

Factory activity in China ended a coronavirus-dominated first half by expanding at a stronger pace in June after the government lifted lockdowns.

Another boost to June shipments was an open arbitrage between Shanghai and London copper prices making it cheaper to import than buy domestically. Dwindling quotas for scrap copper imports also left consumers seeking other forms of the metal.

“A favourable arbitrage window helped copper imports,” said He Tianyu, CRU Group’s China copper demand analyst, speaking after the numbers were released. “The recovery of China demand was also very strong, driven by the construction and infrastructure sectors.”

June imports of copper concentrate was at 1.59 million tonnes, down nearly 6% from 1.691 million tonnes in May but up 8.4% from last June.

Concentrate imports for first half of 2020 stood at 10.84 million tonnes, up 3% year-on-year, according to customs data.

June aluminium exports fell 7.5% to 354,038 tonnes from 382,934.5 tonnes in May, the lowest since February 2019, as overseas demand remains weak amid the coronavirus pandemic.

Exports were also down 30% from last June. China is the world’s biggest producer and exporter of aluminium. (Reporting by Tom Daly in Beijing and Emily Chow in Shanghai; Editing by Christian Schmollinger and Kenneth Maxwell)