Charter Communications (NASDAQ:CHTR) said on Monday that Spectrum has introduced a new 500 Mbps internet plan and has boosted internet speed for existing customers to up to 600 Mbps. Beginning September 17,

Charter is contending with slowing broadband customer growth, defections from the cable TV bundle and a young, expanding mobile business.

The company announced that Spectrum’s internet plans will now begin at $30 a month for 500 Mbps (instead of $50) when bundled and current customers will also have their speeds automatically increased for free to 400 and 600 Mbps.