The monopoly that Valve holds over the PC and Mac games digital download market is killing off competition, or so claims a director at a rival service. Its dominance in the sector with Steam is preventing anybody else launching or maintaining a similar online store.

Steam is more than a digital distribution portal, offering digital rights management for the games publishers and a multiplayer platform for consumers, but it is the sales aspect that is deterring rival businesses from taking on owner, the Valve Corporation.

Talking to games industry trade magazine MCV, the (unnamed) director said: "Steam is killing the PC market and it is no wonder digital retailers are failing".

"Steam is locking down the market".

It is believed that at least two digital retailers are in serious financial trouble, although some publishers are starting to also look outside of Steam for digital sales opportunities, including Sega and Sports Interactive who produced Steam-free SKU (stock keeping units) for Football Manager 2011. Because of this, other retailers can carry the title.

Many more publishers will have to follow suit for the market to become more competitive, though, and, according to MCV's source, that seems unlikely: "Publishers don’t give a shit, they don’t care what happens to the customer", he said.

Do you buy all of your PC games from Steam? And, if so, why? Let us know in the comments below...