Moody's Investors Service downgraded the credit rating of SK Telecom Co. on Wednesday in the latest move by global credit appraisers to lower the rating of South Korea's biggest mobile carrier after its takeover of a chipmaker.

   Moody's cut the credit rating of SK Telecom by one notch to A3 from A2 and gave a negative outlook on the mobile operator, it said in a statement.

   The downgrade reflects the expected weakening of the company's financial profile after its acquisition of a 21.05 percent stake in Hynix Semiconductor Inc., the Hong Kong-based agency said. The deal, the largest acquisition ever by SK Telecom, was worth 3.4 trillion won (US$3.03 billion).

   SK Telecom purchased South Korea's second-largest chipmaker in a bid to diversify its business portfolio, even as some market watchers remained doubtful about synergies between the two firms.

   The move follows credit downgrades on SK Telecom by other major rating agencies following the completion of the takeover on Tuesday.

   Standard & Poor's Ratings Services lowered the long-term corporate credit rating and senior unsecured debt rating on the mobile carrier to A- from A. Fitch Ratings has also cut SK Telecom's rating to A- from A. (Yonhap News)