SAO PAULO, May 8 (Reuters) - Shares in Brazilian pork and chicken processor BRF SA rose almost 14% in early afternoon trade on Wednesday after the company reported strong quarterly results on better pricing in export markets and lower grain costs.

The company said it earned a net 594 million real ($116.88 million) in the first quarter, which is seasonally weaker than the preceding one, beating the average of analysts' expectations of a 449.79 million real gain.

Analysts at BTG Pactual said in a note to clients that BRF's performance was "impressive."

"When you combine a favorable commodity cycle, a management team focused on the core business, and a competitor facing challenges fulfilling its growth promises, this is the result," they said.

Executives said on Wednesday that results should remain strong in coming quarters based on the expectation of lower production costs, better demand in Brazil, and a positive outlook for exports.

They also noted all five meat plants BRF owns in Rio Grande do Sul state, where heavy flooding left entire towns under water, killed livestock and destroyed critical infrastructure, are operating again after interruptions caused by the torments.

Measures to improve operating efficiencies, including shortening meat inventory turnover times and reducing the number of animals that die before they can be processed, should also continue to bolster results.

"Our sector has seasonality but when the fundamentals change, you can operate better," Chief Executive Miguel Gularte said.

Chief Financial Officer Fabio Mariano said plentiful global soy and corn supplies should keep a lid on feed costs, helping overall margins. The harvesting of Brazil's second corn crop, around the middle of the year, should have a positive effect on costs and margins in the third quarter, he added.

Management also said the outlook for sales on the Brazilian market is better than last year based on rosier employment and household income data.

BRF executives also noted chicken prices in export markets may continue to improve while confirmation of more export permits will continue to give it flexibility to redirect sales to more profitable markets. ($1 = 5.0822 reais) (Reporting by Ana Mano; Editing by Michael Erman and Chris Reese)