MELBOURNE, June 6 (Reuters) - Alliance Minerals Assets Ltd, which began exporting lithium concentrate from theBald Hill project in Western Australia in May, said on Wednesdayit has doubled its estimate of lithium ore reserves.

Singapore-listed Alliance began lithium and tantalumconcentrate production in mid-March as part of a joint venturewith Tawana Resources  , which it bought out for A$215million ($165.4 million) in April, in a deal that is expected tobe completed by the fourth quarter. [nL4N1RI235] Bald Hill produces spodumene, a type of lithium concentratethat is in hot demand to be processed into lithium carbonate orhydroxide for use in rechargeable batteries that power mobilephones and electric cars.

The joint venture put lithium resources at 11.3 milliontonnes at 1.0 percent of lithium oxide, up 105 percent from itsJuly 2017 estimate, it said in a filing to the Australian stockexchange.

The partners are reviewing options for significant expansionin processing capacity and concentrate production, the statementsaid.

" There is strong demand for our product. We had a fairly lowcapital spend on the first plant, so we are looking at eitherincreasing throughput for that or building another one," TawanaResources Managing Director Mark Calderwood told Reuters.

" We aim to continue to grow resources and reserves ... We' llprobably have another resource upgrade later in the year." Shares in Alliance rose more than 4 percent on Wednesday ina slightly firmer broader market.

Two shipments were completed in May and the next shipment is anticipated in late June or early July, it said.