UPDATE 3-Mexico's Cemex posts better-than-expected 3rd qtr profit

(Adds share price)

MEXICO CITY, Oct 26 (Reuters) - Mexican cement producer Cemex reported a better-than-expected rise in third-quarter profit on Thursday, up 1 percent on a lower tax burden and lower financial costs.

Cemex's third-quarter profit rose to $289.2 million from $285.6 million a year earlier, it said, prompting shares to rise on Thursday more than 2 percent, hitting 15.84 pesos ($0.8327) a share.

Sales rose to $3.55 billion from $3.47 billion a year earlier. Analysts surveyed by Reuters expected Cemex to have $3.48 billion in revenue and $181 million in net income.

Cemex, which has operations in more than 50 countries, said it generated some of its third-quarter profit from its $168 million sale of shares in Mexican cement maker Grupo Cementos de Chihuahua in September, a move meant to reduce debt.

The company has been divesting assets to help cut debt and regain its investment grade rating.

During the quarter, Cemex had to contend with natural disasters in key markets.

Cemex said that in Mexico, where net sales rose 7 percent over the quarter, "construction activity was affected by natural disasters including earthquakes, hurricanes and heavy rains."

In the United States, where net sales were down 3 percent for the quarter, Cemex said cement volumes increased 2 percent, "despite significant precipitation and two hurricanes - Harvey that impacted Houston, and Irma that impacted Florida, Georgia and Tennessee."

The Monterrey-based company's stock has fluctuated over the past 12 months, swinging from a low of 14.55 pesos in November to a high of 19.27 pesos in January.

Cemex closed trading on Wednesday at 15.52 pesos a share.

($1 = 19.0439 Mexican pesos) (Reporting by Daina Beth Solomon and Noe Torres; Editing by Frances Kerry)