LinkedIn, the professional networking service that recently agreed to be acquired by Microsoft for $26.2 billion, may have lost out on millions.

Previously, LinkedIn had been entertaining bids from Salesforce.com, the San Francisco cloud computing business, before deciding to negotiate with Microsoft exclusively.

Now, Salesforce chief executive Marc Benioff says he would have paid significantly more for LinkedIn than Microsoft did -- and offered a different mix of cash and stock -- had the companies continued to communicate, according to a LinkedIn regulatory filing published Friday. Benioff said as much in an email to LinkedIn chief executive Jeff Weiner and co-founder and chairman Reid Hoffman, after reading a July 1 regulatory filing that detailed events leading up to LinkedIn's "final call" for offers.

Still, LinkedIn claims that the most recent Salesforce bid -- which came in after the exclusivity agreement with Microsoft had been signed -- did not include a higher price than what it had previously offered. The board met on July 7 to discuss Benioff's email.

It's unlikely that the news will impact the price tag on LinkedIn, however, inasmuch as the company said it preferred the all-cash nature of Microsoft's bid, which is $196 per share. It's also worth pointing out that a stock-and-cash deal, as Salesforce was offering, is inherently riskier, and would have required approval from LinkedIn shareholders.

The network could still accept another bid if it comes in, though that would require paying a $725 million breakup fee to Microsoft --  which seems unlikely to happen.