(Adds background, construction and manufacturing breakdown)
MEXICO CITY, July 10 (Reuters) - Mexican industrial output took its steepest drop in more than a year in May as manufacturing and construction activity tumbled, pointing to further headwinds for Latin America's second-largest economy.
Industrial output sank by 0.4 percent in May from April, the national statistics agency said on Friday. That was below expectations for a 0.2 percent expansion in a Reuters poll and the biggest decline since September 2013.
Factory output slid by 0.9 percent. Mexico sends nearly 80 percent of its exports, mostly factory goods, to the United States.
The construction sector, which also is a component of industrial production, shrank 1.5 percent.
In the first quarter, Mexico's economy grew at its slowest pace in more than a year, undermined by flagging oil production and weak U.S. demand for exports.
Data on Friday, however, showed mining expanded by 0.7 percent, with oil and gas extraction rising 1.2 percent.
Mexican crude production has been declining, and a slump in global oil prices has dampened expectations for a tide of investment under the country's recent opening of its energy sector to private investment.
Compared with May 2014, industrial output fell 0.9 percent , missing expectations for a 0.5 percent expansion. (Reporting by Alexandra Alper; Editing by Lisa Von Ahn)