A hot potato: PlayStation CEO Jim Ryan has responded to Microsoft's offer to keep the Call of Duty series available on the PlayStation for three years after Activision's contract with Sony comes to an end. Far from being happy about the commitment, Ryan says it is "inadequate on many levels."

Xbox boss Phil Spencer last week said that Microsoft is committed to keeping Call of Duty on PlayStation for several more years beyond the current deal Sony has with Activision, which covers the series' next three releases, including October's Call of Duty: Modern Warfare II.

The comments came after the UK's Competition and Markets Authority regulator expressed concerns over Microsoft "withholding or degrading" Activision Blizzard content from other consoles or subscription services if the $68.7 billion acquisition goes through.

Speaking to GamesIndustry.biz, PlayStation boss Ryan expressed his dismay at Spencer speaking publicly about the deal. "I hadn't intended to comment on what I understood to be a private business discussion, but I feel the need to set the record straight because Phil Spencer brought this into the public forum," said Ryan.

"Microsoft has only offered for Call of Duty to remain on PlayStation for three years after the current agreement between Activision and Sony ends. We want to guarantee PlayStation gamers continue to have the highest quality Call of Duty experience, and Microsoft's proposal undermines this principle."

Fears of what could happen to Activision Blizzard's games in the wake of Microsoft's acquisition have been around from the beginning. Confirmation that the next three games in the series would be released on the platform came in January, but there has been little word on what will happen to the wildly popular franchise's PlayStation existence once the contract expires.

Some vague non-exclusivity promises from Microsoft arrived in February, but Sony last month voiced concerns to Brazil's competition regulator about what might happen to PlayStation titles like CoD if the acquisition is approved. Microsoft's defense was to deny its purchase would damage the industry, accuse Sony of being afraid of Game Pass, and call the company hypocritical in light of its own exclusivity deals.

Sony also believes that if another studio made a game similar to CoD, it wouldn't replicate the long-running shooter's success, given Call of Duty's dedicated and extensive fan base. The Japanese giant also stands to lose a lot of money if CoD does eventually disappear from the PlayStation as the series is one of the largest sources of revenue from third-party publishers on the platform.