(Reuters) - Microsoft Corp's (>> Microsoft Corporation) $26.2 billion purchase of LinkedIn Corp (>> LinkedIn Corp) on Monday invoked scorn from the professional network's loyal users and shocked traders who expressed surprise on other sites.

"Oh-oh, What will Microsoft Do to LinkedIn?" Saul Marcus, a business analyst at Commonwealth of Massachusetts posted on LinkedIn, an online network of 433 million professionals.

Marcus' post was one of thousands about the deal made in the hours after the announcement.

One LinkedIn user, Phil Thomson, said he would no longer use the networking site.

"I regret to inform all my connections that I will no longer be accepting invitations or messages on LinkedIn, due to its sale to Microsoft," wrote Thomson.

"It was a pretty shocking way to kick off a summer Monday," said a social media manager at StockTwits.com, an online site where users message almost exclusively about stocks. He said that most of the posts he'd witnessed were from surprised traders.

"I thought LinkedIn was a decent company. Buyout by $MSFT indicates that it no longer is," posted David Trentham, who identified himself as an investor.

Microsoft has had a rough track record in making big acquisitions pay off, and in the last three years, it has had to write off about $14 billion related to its earlier takeovers of Nokia in 2014 and digital ad agency aQuantive in 2007.

In May 2011, the company signed a deal to buy online video chat company Skype for $8.5 billion, a price analysts considered high at the time. It's unclear if the investment had paid off as the company has not divulged financials of the service.

The same can be said of its $2.5 billion investment in the Swedish game developer behind the wildly popular video game Minecraft, which also trended on social media Monday when it opened up cross-platform gaming for the first time.

(Reporting by Melissa Fares)

By Melissa Fares

Stocks treated in this article : Microsoft Corporation, LinkedIn Corp