The fifth seeded Indo-Spanish pair lost 5-7 5-7 to third seeded Russian pair of Ekaterina Makarova and Elena Vesnina in the finals of the hard court event which lasted for one hour and 36 minutes.
Playing her fifth final of the season, Sania failed to cross the last hurdle once again as her opponents converted the chances that came their way.
Sania and Nuria saved seven of the 13 break points, while their rivals saved six of the 10 break points.
While returning, the Indo-Spanish pair converted four out of 10 break points, while Makarova and Vesnina made use of six chances out of the 13 that came their way.
Sania won two titles this season, one with Australian Anastasia Rodionova (in Pattaya) and one with American Bethanie Mattek-Sands (in Brussels). She ended runners-up with Vesnina at Dubai and Indian Wells.