New Delhi, Oct. 23 -- Infosys Ltd reported its slowest second-quarter performance in at least a decade on Friday, capping a modest quarterly outing for the country's five largest tech services firms. The company's ADRs (American Depositary Receipts) tumbled on the New York Exchange, as India's second-largest information technology (IT) services firm dialled down its revenue guidance for the year.

Infosys ended the July-September period with $5.15 billion in revenue, marginally below a Bloomberg poll estimate of $5.18 billion. Three-fourths of the revenue growth-up 1.24% sequentially and 1.3% from a year earlier-came from energy, utilities and resources firms, which make up more than a tenth of its business.

With this, the country's five...