Korean Air Co. said Tuesday that Britain's antitrust regulator has expressed concerns over its planned integration with smaller local rival Asiana Airlines Inc., citing monopoly worries on routes between the two countries.

In a statement released Monday, Britain's Competition and Markets Authority said the buyout of Asiana by Korean Air could lead to higher prices for passengers flying between London and Seoul, as well as impacting air cargo services.

"Korean Air and Asiana Airlines are the two main players on the London to Seoul route and the deal risks UK customers and businesses paying over the odds or receiving a lower quality of service," Colin Raftery, senior mergers director at the CMA, said in the statement.

Should Korean Air and Asiana Airlines fail to address our concerns, this deal will progress to a more in-depth investigation, he said.

In response, Korean Air said, "We are on the right track to finalize the process and will soon submit the updated remedies after discussions with the CMA."

The national flag carrier said it will continue to cooperate closely with the CMA and the remaining authorities to complete the merger process.

In January last year, Korean Air submitted documents to antitrust regulators in 14 countries for the review of its combination with Asiana.

The company has received approval from nine countries -- Australia, South Korea, Singapore, Vietnam, Thailand, Turkey, Taiwan, Malaysia and the Philippines -- so far for the integration while awaiting the go-ahead from five countries -- China, Japan, Britain, the European Union and the United States.

Korean Air, currently the world's 18th-largest airline by fleet, will become Asiana's biggest shareholder with a 63.9 percent stake if the acquisition is completed.

In November 2020, Korean Air signed a deal to acquire the controlling stake in Asiana in a deal valued at 1.8 trillion won ($1.5 billion) that would create the world's 10th-biggest airline by fleet.

The nation's two full-service carriers account for a combined 40 percent of passenger and cargo slots at Incheon International Airport, South Korea's main gateway, below the level that constitutes a monopoly.

Korean Air aims to launch a merged entity with Asiana in 2024 after completing a takeover process by next year, vowing to streamline their routes and reduce maintenance costs. (Yonhap)