France striker Giroud, 30, has returned to the side in recent weeks to score four goals in as many appearances, including his scorpion kick effort in the win over Crystal Palace
Coquelin, 25, has developed into a key member of the first-team squad following his return from a loan at Charlton in December 2014 while centre-back Koscielny has proved a consistent performer since joining from Lorient in July 2010
Gunners boss Arsene Wenger believes the contract extensions are just reward for each of the players' own hard work
"We are very pleased that three important members of our team have committed to us for the long term," Wenger said on the club's official website, www.arsenal.com
"Francis has made tremendous technical strides over the past few years because he's so focused every day
"Olivier has big experience in the game now and has become a more and more complete player since joining us.
"Laurent is of course a key part of our squad and I believe one of the best defenders in the world today
So overall, this is great news for us."
Arsenal are also looking to negotiate new deals with key men Mesut Ozil and Alexis Sanchez
Wenger, meanwhile, has himself yet to formally announce any plans following the end of his current contract, which expires in the summer
Source : PA