UPDATE 1-Molycorp warns on first-half revenue, shares fall

Jan 23 (Reuters) - Rare earth producer Molycorp Inc warned of significantly lower revenue and cash flow for the first half of the year and said it might have a cash shortfall of about $250 million for the year, sending its shares down more than 10 percent premarket.

Fourth-quarter revenue and cash flow were also significantly less than expected, the company said in a regulatory filing on Wednesday. ()

The miner also forecast production for the fourth quarter and the first half of 2013 to be substantially lower than expected due to a delay in achieving full production at its Mountain Pass, California processing plant.

Molycorp warned earlier this month that it expects its Mountain Pass plant to achieve Phase 1 commercial production rate of 19,050 tonnes of rare earth products a year by mid-2013, having failed to meet its 2012 year-end deadline.

The company also said Project Phoenix, its expansion and modernization project at the plant, will cost an additional $80 million to complete. It expects capital expenditures of $1.34 billion at the plant.

Separately, Molycorp said it will sell $200 million of its shares and $100 million in convertible senior notes in two separate public offerings to fund capital expenditures in 2013, including costs at the Mountain Pass plant.

Molycorp shares, which have lost 50 percent of their value over the last six months, were quoted down 10 percent at $7.98 in premarket trading on the New York Stock Exchange on Wednesday.