By Denny Thomas HONG KONG (Reuters) – Every big bank in town wanted a piece of the Alibaba Group Holding Ltd initial public offering, set to be the biggest technology listing ever. So much so that, according to Thomson Reuters data, major banks skipped an estimated $100 million in combined fees they could have made from work for other clients over the past year. People familiar with the matter say thats because the banks didnt want to irk the Chinese e-commerce giant by working for its rivals or acquisition targets, and risk losing out on business in an IPO expected to be bigger than Facebook Incs $16 billion listing in 2012. Alibabas giant IPO comes amid a wave of deals in Chinas tech sector, putting banks in a tricky situation when it comes to backing clients in the industry.