Microsoft and Amazon have faced probes in Britain, the EU and the US over their power in cloud computing. Google is far behind the two leaders. Microsoft's link-up with ChatGPT maker OpenAI has also raised worries.

Google Cloud boss Amit Zavery said: " We are concerned about Microsoft using their old tricks where they had a lot of monopoly on the software before and now they are trying to do that in cloud now. So they are making this whole closed garden, which is totally run and owned by Microsoft, and customers who want to do any of this stuff, you have to go to Microsoft only." 

"If Microsoft cloud doesn't stay open, we will have problems and long-term issues, even in next generation technologies like AI as well, because Microsoft is forcing customers to go to Azure in many ways," Zavery said, talking about Microsoft's cloud computing service.

He called on watchdogs to act.

"I think watchdogs need to give some kind of advice as well as maybe rules which stop the way Microsoft is building the Azure cloud business, not let your software monopoly turn into a cloud monopoly," Zavery said.

Microsoft brushed off that argument.

"As the latest independent data shows, competition between cloud giants is still healthy," said a spokesVole. "In 2023, Microsoft and Google made small gains on AWS, which continues to be the global market leader by a big margin."

Zavery also attacked Microsoft's deals with individual cloud vendors, saying these ignore the bigger issues. Trade group CISPE last month said it was talking to Microsoft to sort out its EU antitrust complaint about its cloud computing licensing practices.

"Microsoft has been very clever, picking individual vendors who moan and do one-side deals but they don't solve the bigger problem. So they can pick the winners and losers in many cases as well, so they kind of pick who they want to compete with," Zavery said.

Microsoft denied the criticism.

"We have listened to and worked well and directly with independent cloud providers to change our licensing terms, dealing with their worries and giving them more chances. Worldwide, more than 100 cloud providers have already used these changes," a Microsoft spokesVole said.