After facebook, Twitter, now LinkedIn is focusing on its “new share button”.

With just a few lines of code, publishers, bloggers and businesses can easily include a button on their site that lets readers and visitors “Share on LinkedIn” said a blog post in LinkedIn.

In the past, publishers like The Huffington Post have integrated LinkedIn share on their websites. Now, sites like Bloomberg, Forbes, and the Mercury News’ are doing the same. They are also integrating even more advanced functionality like the ability to sign-in to your site with LinkedIn credentials, which one can learn more about in LinkedIn. Some of the big share buttons are Twitter, Stumble Upon, Facebook, Digg and others.

“As a professional, we know the importance of staying up-to-speed on industry trends and business news and now we have made it easier for you to share that news and research with your team, clients, and peers from your favorite business news sites,” said a posting on LinkedIn blog.

Now in LinkedIn, publishers can choose between three flavors of the share button: vertical with a share counter, a smaller, horizontal button with the counter, or a horizontal button with no counter.

For LinkedIn, this new share provides another avenue to create discussions among its members, though it does not have the same volume of members as Facebook. But it has specific groups of professionals who use it to share business or technical info from the web with others in the group.

Since most of the publishers have already kept their place in Twitter, Facebook and others sites, LinkedIn might face strong competition.