MELBOURNE/SANTIAGO July 15 (Reuters) - Choppy seas off the coast of Chile caused widespread delays to copper shipments from the world's top producer in the second half of June, potentially supporting prices in a market grappling with oversupply.
Cargoes were stranded at ports as stormy weather prevented ships from loading, said miners in Chile, including world No.1 Codelco.
That could buttress prices in the short-term, although any impact is unlikely to last long as miners said exports were back to normal by the start of this month.
Delays could also hit import data for the month of July in top metals consumer China, with numbers due to be released next month.
"In the second half of June, the ports were closed for several days in a row due to weather issues, delaying shipments," a Codelco spokesperson told Reuters.
"However, in early July all those shipments were regularized."
Chile accounted for 30 percent of global mine supply last year, at 3.8 million tonnes, and around 20 percent of global refined copper supply, Reuters data shows.
Its copper export revenues were down 16 pct in June from a year ago, according to data from the country's central bank.
A spokeswoman for Chile's second-biggest copper mine Collahuasi, owned by Anglo American Plc and Glencore Plc , said its exports had been curbed by the rough waters, but declined to give further details.
"Historically we always have this kind of disruption caused by weather and this may have a short-term positive impact on the copper price," said analyst Helen Lau at Argonaut Securities in Hong Kong.
Lau said that lower imports in July may cause concern about the strength of Chinese demand, but that any impact should be offset by a rise in August figures.
A trader said that a disruption in metal shipments may boost premiums for refined metal, but would have a limited impact on the "flooded" market for concentrate. He declined to be identified as he was not authorised to speak to the media.
Copper mine supply is expected to grow by 5 percent this year as new projects, mainly in Peru, come online.
Premiums for copper shipments to Shanghai on a cost, insurance and freight basis edged up by $2.50 to $52.50, from four-year lows of $35 in mid-June, the latest data showed CU-BPCIF-SHMET.
China's copper imports dipped 2.3 percent in June to 420,000 tonnes from a month earlier, but were still up 22 percent for the first half, in line with a more orders from China's power sector, its biggest copper user.
Exchange copper stockpiles in China are sitting around nine-month lows at 155,235 tonnes. CU-STX-SGH
Reporting by Melanie Burton in Melbourne, Fabian Cambero and Anthony Esposito in Santiago; Additional reporting by Rosalba O'Brien in Santiago; Editing by Joseph Radford