SAN FRANCISCO -- Microsoft is reportedly among a handful of tech giants looking into a possible acquisition of, a cloud pioneer that saw meteoric growth in recent years but of late has been challenged by a new wave of upstarts, including Netsuite, Zoho and SugarCRM. Microsoft may indeed be the most likely candidate to acquire Salesforce, as the two companies have recently put aside some of their competitive differences to partner on new offerings.

Among other things, Microsoft has worked to integrate parts of Salesforce’s customer relationship management technology into its Office 365 cloud, and the company now offers a Salesforce app on its Outlook Apps store. This is despite the fact that the Redmond, Washington, tech multinational continues to compete head-to-head with Salesforce in some segments of the CRM market through its CRM Online suite.

Microsoft benefits from closer ties with Salesforce because it allows users to access Salesforce tools without leaving the Office 365 environment.

“You can’t label any relationship just competitor or partner,” said Takeshi Numoto, Microsoft’s corporate VP for cloud and enterprise marketing, in an interview with International Business Times Thursday at the Build 2015 conference. “We compete with Salesforce in some areas like CRM, and we partner deeply in some other areas.”

Microsoft also plans to release a Salesforce 1 app for Windows Phone later this year.

Microsoft is not commenting on the reports. Other potential buyers include a handful of tech giants that are also looking to bolster their cloud portfolios, including IBM, SAP and Oracle. Salesforce CEO Marc Benioff was formerly an Oracle executive.

The rumors were sparked Wednesday, when Bloomberg reported that Salesforce had engaged investment bankers to explore strategic options. The report caused Salesforce’s stock (CRM:NYSE) to jump more than 13 percent at one point. It closed down 2.45 percent Thursday, at $72.82.