A week ago it was reported that Salesforce.com Inc., the largest employer in San Francisco's tech sector, was at work with financial advisers after receiving takeover offers. At that time, sources said that a potential mystery acquirer had approached the company, and it was a big "Whoa, if true" moment.

Now there's a bit more corroboration in the form of another potential takeover offer. No, this one isn't Oracle, as was speculated, although that might be an additional offer on the table. Also, in speaking to the Business Times recently, that company's CEO said that a Salesforce buyout would be good for them.

No, today's potential buyer is none other than Microsoft Corp. And, interestingly, Bloomberg is reporting that the company, which represents a cloud computing rival to Salesforce in its own right, is evaluating its bid for Salesforce because of the recent news that Salesforce might be for sale in the first place. Maybe it's just rumor becoming reality, or maybe it's all rumor, but its certainly worth exploring.

Salesforce has a market value of nearly $50 billion, so it's a big buy for anyone. And, in addition to cloud computing, it should be noted that Salesforce occupies a highly favorable position in customer relationship management, or CRM.

Though we do know that Microsoft isn't actively in talks with Salesforce, meaning nothing is "imminent," we can also look back to last year, when Microsoft and Salesforce found some common ground, reaching agreement to make their enterprise software play better together. And just last week Microsoft announced its goal of increasing annual revenue from its commercial cloud business to about $20 billion, so having Salesforce on board would sure help.

A quick side note: We now know that Salesforce was involved in discussion with with SAP, another competitor, last year. These days SAP has said that it’s not considering a bid for Salesforce at this time.

As CNBC reports, shares of Salesforce were higher yesterday afternoon when the Microsoft news was first reported. But it sounds like pundits still think of Oracle as a more likely buyer. "Whether Microsoft would make a serious bid, I'm more doubtful. I think Oracle probably makes the most sense," said Rick Sherlund, director of technology research at Nomura Securities.

Previously: Salesforce For Sale? SF's Largest Tech Employer Works With Bankers To Field Takeover Offers