Higher other income, foreign-exchange gains and tax savings aided Tech Mahindra's earnings in December quarter (Q3), which grew a whopping 32.8 per cent sequentially to Rs 856 crore, coming way ahead of Bloomberg consensus estimate of Rs 758 crore. However, this may not be sustainable as earnings are driven by a surge in non-core, unpredictable income streams mentioned above. High growth in earnings nearly eclipsed healthy revenue growth in Q3. One-month revenue from Target acquisition, coupled with strength in enterprise and telecom verticals, led to a 5.4 per cent sequential growth in constant-currency revenue. This is highest growth registered by