It has been reported that three major health insurers were pursued a deal that was signed this week between Aetna Inc. and Humana Inc. UnitedHealth Group Inc., Anthem Inc. and Cigna Corp were lurking around the discussions regarding the deal.

According to reports, both Aetna and Cigna were following Humana. Sources knowing about the talks revealed that. In the meantime, Cigna was saying no to advances from Anthem and its $47.5 billion bid for Cigna last month was revealed after it failed to reach a deal when it approached the company privately.

It raised many concerns for the Humana regarding Cigna's assurance to the purchase, such as whether it was really looking forward to buy Humana, or wanted to yield a deal with Anthem. According to sources, Humana was concerned that Cigna was doing that to make itself more attractive for Anthem.

According to a source, Cigna that has been carrying out discussions with Anthem also showed interest in Humana on Thursday evening. The deal with Aetna was announced after 2 am EDT on Friday.

According to sources familiar with the matter, Humana asked Cigna to come up with a cash-heavy offer, however Cigna didn't do that. Humana was concerned that Cigna shareholders might not say yes to a Humana takeover in view of Anthem's attractive offer. Its shareholders' approval is required for any takeover bid.

Cigna's board could progress in the face of the Anthem offer under discussion for the reason that Cigna shareholders' approval would not be needed in a cash bid.