Martin Marietta Materials announced this morning that increasing demand for its products in the fourth quarter helped the company boost sales by 13 percent.

The Raleigh company, which produces rock, gravel and other materials used to build roads, subdivisions and commercial buildings, had sales of $368.8 million for the quarter that ended Dec. 31, up from 327.8 million in the same period in 2009.

Earnings per share were 32 cents, compared to a loss of 7 cents in the fourth quarter of 2009.

For the year, sales were $1.551 billion, up four percent from 2009.

Earnings per share for the year were $2.10, compared with $1.91 the previous year.

That easily beat analysts expectations.

"Our financial results in October and November provide further validation of our previously stated view that volume recovery, combined with our lean operating cost structure, will lead to profit margin increase even without price increases," CEO Ward Nye said in a release.

Nye said the increase in sales in the fourth quarter was supported by an increase in state transportation spending and spending in the energy sector.

For the year, Martin Marietta's shipments grew 5 percent.

Martin Marietta's outlook for next year will depend heavily on federal infrastructure spending.