SEOUL, Sept. 15 (Yonhap) -- Senior Secretary to President for Public Relations Kim Du-woo offered to step down on Thursday over allegations he had ties to a lobbyist at the center of a corruption scandal involving a troubled savings bank.

Kim submitted his resignation to Presidential Chief of Staff Yim Tae-hee, who then reported it to President Lee Myung-bak, said presidential spokesman Park Jung-ha, adding the resignation will be processed according to procedure.

The move comes after prosecutors on Thursday decided to summon Kim on charges of being lobbied by Park Tae-gyu.

The 71-year-old lobbyist is suspected of taking more than 1 billion won ($899,281) from the corruption-ridden Busan Savings Bank with promises that he would lobby senior officials and politicians so that the lender could avoid a suspension of operations.

Kim said the key reason for his departure is due to the prosecutors' request for an investigation and that it is not right to serve as a presidential aide while being under such a probe, according to spokesman Park.

Kim stressed he has known Park Tae-gyu for around 10 years, but has never done any favors for the lobbyist nor received cash in return, the spokesman said.