(Reuters) – Miner Freeport-McMoRan (NYSE:FCX) Inc reported a 60% slump in second-quarter profit on Thursday, hurt by a drop in production and lower sales due to shipping delays in Indonesia.

Freeport operates the low-cost, high-grade Grasberg mine in Indonesia and its export permit expired on June 10, when the Southeast Asian country began its raw mineral export ban. The company has not made any shipments since the expiry.

A routine 75-day maintenance shutdown at domestic buyer, PT Smelting, since May 1 piled more pressure.

The largest copper producer in the world said quarterly sales of copper fell to 1.03 billion pounds from 1.09 billion pounds a year earlier.

Average realized prices fell to $3.84 per pound, from $4.03 per pound.

Freeport reported a net income of $343 million, or 23 cents per share, in the three months ended June 30, compared with $840 million, 57 cents per share, a year earlier.

The miner’s adjusted earnings of 35 cents per share narrowly beat analysts’ estimate of 34 cents, according to Refinitiv data.