jeff weiner linkedinBusiness social network LinkedIn posted mixed third quarter results this afternoon, with a $1.6 million loss for the quarter, but it’s still managing to beat Wall Street expectations with strong revenues.

LinkedIn went public in May and had to reveal its financials for the first time last quarter. The company posted a surprisingly strong Q2 with a 120 percent rise in revenues and $4.5 million in profits. But this is Q3 and it’s unfair to directly compare it to last quarter.

In the third quarter, LinkedIn reported $139.5 million in revenues, which is up 126 percent from Q3 2010. Unfortunately, in terms of profits, it was down with a loss of $1.6 million compared to a net gain of $4 million in Q3 2010. Earnings per share was a negative 4 cents a share.

Even with this being an unprofitable quarter, the social media company beat Wall Street analysts’ expectations. Analysts had expected the company to only earn $128 million in revenues.

“LinkedIn had a strong third quarter, with significant, broad-based growth across all of our revenue streams, member engagement metrics, geographies and sales channels,” said LinkedIn CEO Jeff Weiner (pictured) said in a statement. “Our results underscore the long-term strength of our global platform and our business model.”

The biggest bright spot was LinkedIn’s membership numbers, with 131.2 million registered users now on the site. That’s an increase of 63 percent from Q3 2010, indicating sign-up momentum.

LinkedIn’s share price closed today at $87.50, but is down nearly 9 percent in after hours trading. When LinkedIn debuted on the New York Stock Exchange in May, it closed its first day of trading at $94.25.

Although LinkedIn had a not-so-great quarter financially, the company has done well with recent product introductions and innovative changes to its service. In mid-October, it launched a new Classmates feature that makes it easier to connect with alumni and a headhunting-like service targeting job recruiters.