Comcast and Time Warner Cable on Friday announced they had scrapped their mega-merger plans, amid opposition from US antitrust regulators.

"Today, we move on," Comcast chairman Brian Roberts said in announcing the end of a $45 billion deal to merge the two cable and broadband giants. "Of course, we would have liked to bring our great products to new cities, but we structured this deal so that if the government didn't agree, we could walk away."