Soccer-Juve sign Brazil left back Alex Sandro from Porto

MILAN, Aug 20 (Reuters) - Juventus have signed Brazil left back Alex Sandro from Porto on a five-year contract for a transfer fee of 26 million euros ($29.23 million). The fee for the 24-year-old, who has played six times for Brazil, will be paid over the next three years, the Italian champions said on their website (www.juventus.com) on Thursday. Alex Sandro, who started out at Atletico Paranaense before joining Santos, made 137 appearances for Porto, scoring three goals, and won two league titles and two Portuguese Super Cups. Juve, who claimed the Italian league and cup double last season but lost to Barcelona in the Champions League final, begin their Serie A campaign at home to Udinese on Sunday. ($1 = 0.8896 euros) (Writing by Ken Ferris; editing by Tony Jimenez)