ArcelorMittal , the world's top steelmaker, forecast higher shipments but lower prices in the first three months of 2010 and a core profit that could fall from a fourth-quarter figure that just missed expectations.

The firm, which has about 8 percent of the global market and capacity some three times greater than nearest rival Nippon Steel <5401.T>, said it expected its EBITDA (earnings before interest, tax, depreciation and amortization) to be between $1.8 and $2.2 billion in the first quarter.

The average of a Reuters poll was $2.6 billion, albeit with a wide range of forecasts.

Chief Executive Lakshmi Mittal said 2010 would continue to be challenging, although capital expenditure would rise.

We therefore start the year in a good position to benefit from the progressive, albeit slow, recovery that is underway, he said in a statement.

ArcelorMittal said its shipments were expected to be higher in the first quarter of this year than at the end of 2009, but it would face lower average selling prices and increased costs. Net debt was expected to increase over the period.

EBITDA was $2.1 billion in the final quarter of 2009, against the average $2.23 billion forecast of a Reuters poll of 21 analysts. The company had given a range of $2.0 to $2.4 billion in October.

(Reporting by Philip Blenkinsop; Editing by Sharon Lindores, John Stonestreet)