Customer engagement service Lithium Technologies is reportedly buying the social media analytics startup Klout.

The deal between Lithium Technologies and Klout, which was worth $100 million, has been signed but has yet to close, said a source to Re/code.

Klout, which was launched in 2010, is a startup that ranks online social influence of users with a "Klout Score" of 1 to 100-100 as the highest. It is the product of Klout CEO Joe Fernandez' four-month long stay at a hospital in Singapore where he underwent a surgery that left his jaw wired. The company is backed up by a roster of investors including Institutional Venture Partners, Kleiner Perkins Caufield, Greycoft, and Venrock.

The service works by calculating numerous variables, from the number of times a user's tweet has been retweeted up to the size and influence of their followers in order to assign a numerical "Klout Score."

It has also tried different business models and products like "Klout Perks," wherein users will receive a "gift" if they tweet about them.

However, due to criticisms brought by the vanity of social media, the San Francisco-based Klout was placed in the verge of total closure. It disappeared from headlines and when it reappeared, it brought no good news - the resignation of its COO Emil Michael.

Just in time before Klout shuts down, Lithium Technologies - a savior in disguise - offered it a partnership in preparation for its expected plan to go public soon.

Lithium Technologies is the provider of social customer experience management software for the enterprise. Its platform combines online customer community applications like blogs, forums, and live chat resulting in a broad range of online customer interaction methods.

In September 2013, it had generated $50 million in "pre-IPO mezzanine financing," accumulating a total amount of $150 million from New Enterprise Associates and a syndicate of new global institutional investors.

Both companies have been contacted for comments but have not returned calls yet.