UPDATE 1-Mexico's Alfa 2nd qtr net profit down 15 pct

* Financing costs, forex losses dent net

* Revenues driven by Alpek, Nemak units (Adds revenue details, stock quote)

MEXICO CITY, July 21 (Reuters) - Mexican conglomerate Alfa said on Wednesday its second-quarter net profit fell 15 percent, hurt by higher financing costs and foreign exchange losses, while its sales rose.

Monterrey-based Alfa (ALFAA.MX) earned 766.11 million pesos ($59 million) in the April-June period compared with 905.09 million pesos in the same quarter of 2009, according to a filing with the stock exchange.

Quarterly sales were 33.66 billion pesos, up from 28.08 billion pesos in the second quarter of 2009, helped by Alpek and Nemak, its petrochemical and autoparts units.

Alfa shares rose 0.28 percent to 98.22 pesos in afternoon trading on Wednesday.

($1 = 12.94 pesos at end June ) (Reporting by Cyntia Barrera Diaz. Editing by Robert MacMillan)