By Sinead Carew and Nicola Leske NEW YORK (Reuters) – Cisco Systems Chief Executive John Chambers said on Thursday that the network equipment company is preparing for a long battle to improve its business in China, one that will not be won in a quarter or two. The companys revenue in China fell by 18 percent in the quarter ended in October, a major contributor to a 21 percent decline in the companys top five emerging markets. Cisco said on November 13 that a backlash against U.S. government spying in China contributed to its declining revenue, after a former U.S. spy agency contractor Edward Snowden exposed widespread surveillance – in particular through Internet data, much of which is transmitted via Cisco equipment. It said that the spying scandal, which involved multiple countries, was not a significant issue for Cisco outside of China. Chambers said Cisco is in China for the long run, but he was reluctant to offer much detail on how the company plans to improve its business in the country, where China-based rival Huawei Technologies Co Ltd has been gaining a lot of ground.