* Santander Brasil’s Q3 net profit falls 12.5% * Mexico’s Alsea posts quarterly net profit surge * Brazil’s WEG slumps as Q3 shows fading revenue growth * Latam equities down 0.4%, FX down 0.1% (Updated at 3:50pm ET/1950 GMT) By Johann M Cherian and Lisa Pauline Mattackal Oct 25 (Reuters) – Most Latin American stocks and currencies slipped Wednesday as investors assessed corporate earnings and a rising U.S. dollar and Treasury yields weighed on global risk appetite, though Mexico’s benchmark stock index outperformed on hopes for stronger growth. MSCI’s gauge for Latin American equities was down 0.4% while a basket of regional currencies edged down 0.1% against the dollar. Yields on longer-dated U.S. Treasury notes rose as the U.S. dollar strengthened to a one-week high, as underwhelming corporate results in the U.S. raised concerns over the economic strength of the world’s largest economy However the Mexican stock index rose 0.9%, eyeing its strongest session in over two weeks. A senior finance ministry official said the economy could expand by 3.5% or more this year and largely dismissed concerns that the rising value of the local currency since August was bad for the country’s exports. However, Mexico’s currency fell 0.4%. Colombia’s peso was the region’s top performer, rising 0.7% after China elevated diplomatic relations with the country to a strategic partnership. Emerging markets assets have been under pressure as rising U.S. Treasury yields diminish the relative…