The 41 year old played 990 games in 16 seasons with Montreal
"Andrei will turn 42 this year and he must take care of his family," agent Sergey Isakov told La Presse. "He is a very smart guy and he understands that his time has come."
The Canadiens selected Markov, a native of Voskresensk, Russia, in the sixth round (No. 162) of the 1998 NHL Draft. He played two more seasons in Russia with Dynamo Moscow before joining Montreal for the start of the 2000-01 NHL season.
Markov scored 23 points (six goals, 17 assists) in 63 games as a rookie and then took a leap forward in 2002-03, scoring 37 points (13 goals, 24 assists) in 79 games. Markov had NHL career highs with 16 goals in 2007-08 and 64 points in 2008-09, and played in the NHL All-Star Game each of those seasons.
An ankle injury limited him to 45 games in 2009-10, and he missed all but 20 games during the 2010-11 and 2011-12 seasons with leg and knee injuries. But Markov was healthy again in 2012-13, playing all 48 games during the lockout-shortened season and scoring 30 points (10 goals, 20 assists). He played four more seasons with the Canadiens before signing with Ak Bars Kazan of the Kontinental Hockey League on July 28, 2017.
Markov finished his NHL career with 572 points (119 goals, 453 assists) in 990 games, and 32 points (five goals, 27 assists) in 89 Stanley Cup Playoff games.
"It was his dream to finish his career in Montreal," Isakov said. "He really wanted to, but there's nothing he can do about it. The general manager [Marc Bergevin] only wanted to offer a one-year contract (in 2017), while Andrei was looking for a two-year deal.
"After that, Andrei and I discussed the possibility of a return to Montreal, but it didn't materialize. It's too bad, because he really wanted to play 1,000 games for the Canadiens."
Markov played two seasons for Ak Bars Kazan and 23 games this season for Lokomotiv Yaroslavl.
"Hockey is over for him now," Isakov said. "He wants to spend time with his family."