(Adds details, analyst comment, share movement)
April 23 (Reuters) - British telecoms testing company Spirent Communications Plc reported a 16 percent rise in quarterly revenue as orders rose on the back of a multi-billion-dollar roll-out of 4G networks in China.
Operating profit also rose as revenue climbed to $111.9 million in the first quarter ended March 31. Orders increased 12 percent.
Shares in Spirent, which tests ethernet networks and 3G and 4G wireless networks and devices for companies such as Cisco Systems Inc and Nokia, rose as much as 7.9 percent making it the top percentage gainer on the FTSE-250 Midcap Index .
The company said orders in its second largest unit, wireless and service experience, rose 6 percent due to strong growth in Asia-Pacific on the back of the 4G roll-out.
China has become one of the most important markets for Spirent's testing equipment as the world's second largest economy issued 4G licences at the end of last year to its three telecom carriers.
Huawei Technology Co and China Mobile are among Spirent's clients in China, where spending on 4G LTE networks is estimated by the Chinese government to reach $16 billion this year.
Spirent, said market conditions have improved in all regions from last year.
Last year, Spirent reported a 64 percent fall in profit due to contract delays from major equipment makers in the United States, traditionally its largest market.
The company has since restructured and appointed new executives.
"While the order book appears to have stabilised, the business remains in turnaround and pricing challenges remain," Jefferies analyst Lee Simpson said in a note to clients.
Shares in the Crawley, West Sussex-based company hit a high of 104.2 pence before slipping back a little to 103.1 pence at 0824 GMT.
(Reporting by Noor Zainab Hussain and Tasim Zahid in Bangalore; Editing by Rodney Joyce)