LONDON, Aug 3 (Reuters) - Mexican precious metals miner Fresnillo (FRES.L), the world's largest primary silver producer, said its first-half profit jumped on higher gold and silver production and prices of the metals.

Fresnillo Mining, Mexico

Earnings before interest, tax, depreciation and amortisation (EBITDA) surged 93 percent to $392.0 million as adjusted revenue grew 49 percent.

"We remain positive about delivering robust operational performance in the second half of the year," said Chief Executive Jaime Lomelin.

www.fresnilloplc.com

It plans to pay an interim dividend of 9.20 cents per share, up from 5.25 cents in the year-earlier period.

However, the company said costs per tonne increased at all of its operating mines on the revaluation of the Mexican peso against the US dollar and higher electricity and diesel prices.

The FTSE 100-listed miner reiterated that it was on track to meet 2010 output targets of 38 million ounces of silver and 340,000 ounces of gold.

The miner announced last month that its gold production rose to a record in the second quarter, when prices for the metal also hit new highs.

Concern over euro zone sovereign debt levels drove spot gold XAU= to a record $1,264.90 an ounce in June. Silver XAG= reached its highest price this year in May, although prices for both metals have since receded.

"We believe that the foundations for silver and gold investment will remain positive for the remainder of the year," it said. "However, we remain cautious as we wait to see clearer signs of the strong economic recovery that would drive industrial demand for silver."

Shares in Fresnillo, which rose to a record 1,139 pence in mid July, have increased 34 percent this year on higher gold and silver prices and takeover speculation.

Fresnillo is a unit of Penoles (PENOLES.MX) which is controlled by the Bailleres family.

(Reporting by Julie Crust; editing by Lorraine Turner)