Leyton Orient boss Russell Slade will now remain at Brisbane Road until the end of the 2013/14 season.
Last season saw League One Orient claim their highest league finish in 18 years as well as reach the fifth round of the FA Cup under Slade's stewardship.
Chairman Barry Hearn told the club’s official website: "I'm absolutely delighted that Russell has signed a new long-term contract with the club.
"He has shown himself to be an excellent manager during his time with us, first keeping us in the division and then delivering our best season for a generation.
"His energy and enthusiasm is infectious and we can see what impact that has had over the last 18 months. I'm looking forward to that continuing over the next few seasons too."