Kean was initially appointed until the end of the season and the owner’s feels he had done enough to be rewarded with an extension.
Kean joined Rovers as first-team coach in 2009 and is relishing the challenge of trying to take the club forward over the next two-and-a-half years.
He told the club's official website: "I am delighted to commit my future to Rovers at the start of what I see as a massively exciting new era for the club.
"The owners have shown great faith in me and I will do all I can to repay them.
"This is a great opportunity for me and I intend to grasp it with both hands."
Venky's chairperson Anuradha Desai fully expects Kean to be successful in the job after being impressed by what she has seen from him so far.
"We have great confidence in Steve, someone who impresses us with his work ethic, enthusiasm, positivity and football philosophy," she said.
"We feel that the playing squad is in very safe and capable hands and we look forward to working with him.
"Stability is very important to us and this contract is further evidence of our desire to achieve such stability at the club."
