SEOUL (Reuters) - Hyundai Motor Group, South Korea's second-biggest conglomerate, said on Monday that in an annual reshuffle it has promoted 348 executives, down 5 percent from last year, due to "growing business uncertainty".

The revamp comes as Hyundai Motor Group focuses on slashing costs, including cutting executive pay, after flagship unit and automaker Hyundai Motor <005380.KS> posted its fourth consecutive annual profit decline in 2016.

Big family-owned conglomerates like Hyundai Motor Group and Samsung Group have delayed their year-end annual promotions, after senior executives were questioned by prosecutors investigating a political scandal involving South Korean President Park Geun-hye.

None of the executives of the major conglomerates have been charged with any wrongdoings so far.

Hyundai Motor Group said its management reshuffle "takes into account various situations", but did not elaborate on the change in its timing.

Among those promoted was Jang Woong-jun, who is involved in developing technology for self-driving cars. Jang, who studied at Stanford University, has been promoted to the post of a director, making him the youngest executive of the group at the age of 37.

Hyundai Motor Group trails Samsung Group in terms of assets, and has 51 subsidiaries, including Hyundai Motor, Kia Motors <000270.KS>, Hyundai Mobis <012330.KS> and Hyundai Steel <004020.KS>.

(Reporting by Hyunjoo Jin; Additional reporting by Ju-min Park; Editing by Muralikumar Anantharaman)