Being network savvy can mean the difference between being a manager and being a leader, asserts Herminia Ibarra, INSEAD professor of organizational behavior. Chances are that if you are in management, you have peers who have comparable skill sets, intelligence, and credentials. Ibarra insists that effective global networking is essential to be a business leader today, and claims that “what you know is who you know”. She warns that managers who neglect to build their networks risk failing or remaining stuck in middle management.  

The other difference between managers and leaders is that while many of managers excel at building and utilizing their operational network, they often overlook their personal and strategic networks. Managers might feel that their regular workload is so heavy that they drop the alumni get together or extracurricular activity that they usually enjoy. This is a mistake, as it limits your perspective and vision. If time is an issue (which surely it is) it is better to delegate more day to day work and spend extra time on your personal and strategic networks. This will help you get the edge you need to be an effective in global networking and become a leader.

(http://www.managementtoday.co.uk/search/article/644651/networking-vital-successful-managers/)