Whenever a big merger takes the world by surprise, exhilaration and heartache ripple through Wall Street. Comcast Corp.'s $45 billion agreement overnight to buy Time Warner Cable is no exception.

Goldman Sachs, the perennial leader in the rankings of merger advisers, will come away empty handed should Comcast manage to consummate the deal. That's because Goldman is among the banks that signed up to back Charter Communications Inc's now-thwarted pursuit of Time Warner Cable.