SANTIAGO, June 18 (Reuters) - More than 50 companies

have expressed interest in developing lithium projects in Chile,

Finance Minister Mario Marcel said on Tuesday, after the

government called for proposals for a range of salt flats

containing the battery metal.

Chile, the world's largest copper producer, called for

proposals in April to develop lithium projects in more than two

dozen salt flats that have yet to be fully explored, while

reserving the Atacama and Maricunga brine deposits for state

control.

Fifty four firms from 10 countries submitted statements of

interest to develop 88 projects through the public process,

which ended on Monday, Marcel said at an event in Santiago.

"There are investors of different sizes... there are local

investors and many foreign investors," Marcel said, adding that

"there is clearly a very broad interest in investing in this

industry."

The mining ministry will later provide details on the salt

flats that have received overlapping proposals.

In April, Chile's mining minister said there would be a

tender process if more than one company expressed interest in a

salt flat.

Investors have, however, raised concerns about how the

government will award lithium contracts in salt flats where

mining concessions have previously been granted, which risks

creating a kind of double ownership.

Chile is seeking to build its role in the lithium industry,

which is the world's second largest after Australia, through

state-led projects as well as private investment.

Currently, only U.S. firm Albemarle and local miner SQM

operate in the country. Last month, SQM signed an agreement with

state-run giant Codelco to launch a majority state-run joint

venture.