Vivozon, a privately held biopharmaceutical firm on the over-the-counter (OTC) market, is to become the largest shareholder of Kosdaq-listed Lumimicro.

Vivozon’s move might signal that it is seeking backdoor listing, observers said. Backdoor listing is an easy way to get onto a stock exchange without an initial public offering.

Lumimicro said in a public filing on Tuesday that it signed an agreement to change the largest stakeholders to Vivozon and Boltia (unofficial English name). Under the agreement, Vivozon and Boltia will have 9.11 percent and 12.15 percent stake in Lumimicro after participating in Lumimicro’s rights offering on Dec. 3. As Vivozon CEO Lee Doo-hyun is the largest stakeholder of Boltia, Vivozon will have the controlling rights of Lumimicro.

Observers said Vivozon’s acquisition of Lumimicro seemed to target backdoor listing. Vivozon had sought to be listed on Kosdaq through the technology exception policy within this year but failed to do so after receiving an insufficient rating in technology assessment in June.

“After failing in the technology evaluation in June, we considered not only a direct IPO but backdoor listing and Nasdaq listing,” Vivozon said in a statement on its homepage on Tuesday. “The acquisition of Lumimicro is one of the various options.” The company said it was difficult to confirm anything until it completes the acquisition.

As the company was waiting for the results of a clinical trial, it would decide in January or February next year, it added.

Vivozon is soon to unveil the results of the U.S. phase-3 study on nonnarcotic painkiller opiranserin (VVZ-149). Anticipations for the success of the study boosted the company’s value significantly. Vivozon’s market cap on the K-OTC market is estimated at around 1 trillion won ($854.1 million).