April 30 (Reuters) - Fertilizer maker Mosaic Co ( MOS )

said on Tuesday that Saudi Arabia's flagship mining firm Ma'aden

would acquire the U.S.-based company's stake in a phosphate

production joint venture by issuing shares worth about $1.5

billion.

Ma'aden will issue about 111 million shares to buy the 25%

stake Mosaic owns in Ma'aden Wa'ad Al Shamal Phosphate Co, a

joint venture between Mosaic, Ma'aden and Saudi Basic Industries

Corp.

Mosaic had said in February that a lot of the cash generated

from the asset had gone into reducing debt and investing in the

joint venture was not at the top of its priority.

The phosphate producer curtailed output after fertilizer

prices dropped last year due to lukewarm demand from key

markets.

The deal is expected to close by the end of this year.