Janco Partners analyst Mike Hickey believes Activision’s Modern Warfare 2 will likely be the biggest videogame release of 2009.

The Infinity Ward developed FPS, which is due for release on Xbox 360, PS3 and PC in November, is the direct sequel to 2007’s Call Of Duty: Modern Warfare, which has sold over 13 million copies.

Hickey said he expects the game to sell 11.1 million units by the end of 2009, generating $803 million at retail.

“Given our CY09 sell through estimates for Modern Warfare 2, it’s possible that the game could be one of the largest entertainment releases of all time,” he said in a research note.

“If you assume similar channel unit sales velocity as GTA IV, the game could potentially sell through 7.8 million units globally with an estimated retail value of more than $569 million in the first week. Continuing the same channel logic, it’s possible the game could sell through to consumers’ 4.6 million units globally with an estimated retail value of more than $338 million in the first day.”

Last year Grand Theft Auto IV sold 3.6 million units on its opening day with a retail value of approximately $310 million, and generated over $500 million during its launch week, surpassing the all-time entertainment records for day one and week one sales by dollar value, according to publisher Take-Two.

Hickey’s forecasts echo publisher Activision’s confidence in the game. Last week Activision Publishing CEO Mike Griffith said he expects Modern Warfare 2 to be the bestselling title in the Call Of Duty series to date and “one of, if not the largest, title in the industry this year."