Games retailers pulled out all the stops this week as they clambered to grab share of the biggest ever software launch to hit the market.

The eagerly anticipated Call of Duty: Modern Warfare 2 is the highlight in what has otherwise been a subdued year for the games market.

Sales of the game are expected to break through the 1 million copies barrier in the first week. Specialists including Game and HMV, as well as supermarkets - which have become increasingly big players in the games market and have in the past sparked price wars in the sector - will all want to claim share.

Retailers opened their doors at midnight on Monday when Modern Warfare 2 was launched. Game opened 341 of its 700 UK and Ireland stores and HMV 130 of its 280. HMV said about 7,000 customers queued to buy the game, including 500 at its Trocadero store in London.

The game was also premiered in London’s West End - a first for a computer game.

A Game spokesman said: “We’ve taken record pre-orders for Modern Warfare 2. The launch of a major video game is a huge global event on the scale of Harry Potter books or Lord of the Rings films. Modern Warfare 2 is a very strong contender for becoming the fastest-selling entertainment product of all time.”

An HMV spokesman said: “This is the key blockbuster release compared with the rest of the year, which has been relatively quieter. It will act as a catalyst to get gamers into stores.”

Tesco entertainment director Rob Salter said: “Games have as much money invested in them as blockbuster films and are a really important part of our offer.”

By Tuesday lunchtime, the game had already become the fastest and biggest selling product in the history of

Seymour Pierce analyst Freddie George said: “Modern Warfare 2 is set to be the biggest software launch of all time.”

Singer Capital Markets analyst Matthew McEachran said the new release is likely to be “one of the best-sellers of all time” and, after a “rather lacklustre six months in terms of new releases” will be “welcomed by retailers”.

However, he cautioned: “While this launch is likely to inject some life into the games market, we would highlight that this is not a game aimed at the new generation of family gamers, which has driven much of the industry growth over recent years.”

The biggest selling game to date was Grand Theft Auto IV, released in April last year, which sold 800,000 copies in its first week.