Sasportas, 41, replaces Stella Handler, who resigned as chief of Israel's cable TV company last month.
He has worked at HOT and its predecessor, Golden Channels, for 17 years. For the past eight years, Sasportas has run HOT's planning, infrastructure and technical businesses and was responsible for upgrading HOT's network to accommodate Internet surfing speeds of 100 Mbps.
HOT, which provides multi-channel TV, Internet and fixed and mobile phone services, is a direct competitor to market leader Bezeq.
HOT became a private company in late 2012 when owner Patrick Drahi, a French businessman, bought the remaining shares and delisted the firm.