Delta Air Lines has acquired enough shares to lift its ownership of Korean Air’s parent company almost to its 10% target.

In a filing to the Korea Stock Exchange, Delta said it had boosted its stake in Hanjin KAL to 9.21%, up from the 5.13% in its last report. The Atlanta-based carrier initially bought a 4.3% stake in June, and at that time said it intended to eventually lift its holding to 10%.

Hanjin KAL is the largest shareholder in Korean Air, with a holding of about 29%. Hanjin KAL is controlled by the Cho family, and Walter Cho is the Korean Air CEO.

Delta has previously said its investment will strengthen its relationship with Korean Air, which is one of Delta’s key partners. The two airlines operate a joint venture on transpacific routes.

Adrian Schofield,