Facebook's business rivalry with Twitter is heading to a new high, with the social media pioneer looking to incorporate the relative newcomer's iconic hashtag into its service by using the symbol as a way to group conversations.

Quoting sources close to the matter, The Wall Street Journal reports that "Facebook is testing whether to follow Twitter's lead and allow users to click on a hashtag to pull up all posts about similar topics or events so it can quickly index conversations around trending topics and build those conversations up, giving users more reason to stay logged in and see more ads." However, it's not clear how far Facebook's plans on hashtags have progressed, and the feature is unlikely to be introduced anytime soon.

Instagram, an online photo-sharing and social networking service that Facebook acquired last year already uses hashtags and allows users to sort photos by the symbol. Twitter users use the hashtag, a word or phrase preceded by the "#" pound symbol, to gather Twitter messages about a single news event or topic.

As Wired notes, incorporation of hashtags will provide Facebook yet another way to sell ads in a way similar to Twitter's method of having advertisers pay to promote their own hashtags alongside Twitter's list of most common hashtags.

"On Facebook, advertisers could hypothetically 'promote' user posts that contain particular hashtags just as they now promote 'likes' of their business pages. Such promoted posts could get more prominent and longer-lasting placement on Facebook's News Feed, where non-promoted items are sorted by relevance," the report states.

Facebook and Twitter have been gradually growing in their own spaces, as the former continues to be home of close friends and family while the latter is the real-time broadcasting device for the rest of the world. As the business war began heating up recently, Facebook was seen replicating some of Twitter's features, such as "subscriber" lists for users and letting users tag celebrities and brands with the "@" sign.