merger would have given the new company control of 57percent of the broadband internet market and 30percent of the paid tv market .
announcement that comcast is ` walking away ' from deal could come friday .
comcast has 30million subscribers and time warner cable boasts 11million ; new company would have spun off or sold 3.9 million .
fcc staffers recommended the merger be sent to a judge for review - a significant regulatory hurdle .
regulators questions whether merger was in the public interest .