Spirent Communications reported an 11 per cent rise in first-quarter pre-tax profit, driven by higher demand from telecom customers. The telecoms testing firm was upbeat about its prospects for the rest of the year. For the last quarter its pre-tax profit was $23.6m (£14.3m), compared with $21.3m a year ago. Revenue climbed 14 per cent to $122.8m. Spirent, which tests telecom devices, also said trading performance for the quarter was in line with its expectations. The group, which counts Cisco Systems, Alcatel Lucent and Verizon Communications as customers, said it increased investment in product development by 14 per cent to $21.7m. At the end of 2010 the company had cash and cash equivalents of $215.1m.