Verification efforts are being accelerated, said Ridwan Djamaluddin, the ministry's director general of minerals and coal, without giving an estimate for when the problems will be resolved.

The delays were over procedures designed to ensure that exported tin is legally sourced, Djamaluddin added.

Benchmark tin prices on the London Metal Exchange have hit record highs this week, reaching $43,815 a tonne in Asian trading on Thursday, supported by Indonesia's export licence delays.

The delays centre on whether companies have submitted verified information on their mining reserves and resources.

"One of the goals is to avoid illegal practices," Ridwan told a media briefing, adding that checks were to prevent companies from exaggerating volumes and exporting tin that originated from illegal mines.

Indonesia shipped 74,671.57 tonnes of tin to the global market last year.

State-owned PT Timah, Indonesia's biggest tin miner, on Wednesday said it would begin exporting at the end of the month, as scheduled.

Ridwan on Wednesday said private operators are most likely to face delays.

(Reporting by Bernadette Christina; Writing by Martin Petty; Editing by David Goodman)