UPDATE 1-Indonesia says to impose tin export royalty, ban ore shipment

* Every tin exporter expected to pay royalty charge

* Further Indonesian tin cutbacks supportive of long-term prices

* Indonesia seeks to add value to mineral wealth (Updates throughout, adds detail/comment)

JAKARTA, Aug 12 (Reuters) - Indonesia, the world's top refined tin exporter, will impose a new "royalty" charge on all tin shipments and only allow the export of refined tin, a trade ministry official said on Friday, a move that is expected to lend support to weakening global prices.

Southeast Asia's largest economy, which supplies about 30 percent of the world's tin consumption, expects to produce 90,000 tonnes of refined tin this year, up from 78,965 tonnes last year, on expectations of improved weather conditions.

"Every exporter will have to pay royalty before they can ship the metal," Deddy Saleh, director general of foreign trade at the trade ministry told reporters.

"We are preparing a new regulation on tin export as an amendment to the existing trade minister decree. It is almost final actually."

Under the new rule, the government will not allow export of raw tin -- tin ore and concentrate -- and will only permit refined tin shipments, Saleh added.

"Only tin which (has) its royalty paid by exporters can be shipped for export," Saleh said. This is seen to be consistent with the government's policy to stop non-value added raw material exports within the next three years.