Permanent Secretary of the Federal Ministry of Power, Dr. Dere Awosika, has retired from public service after clocking 60 years retirement age.

Awosika, daughter of Nigeria's first Finance Minister, Festus Okotie-Eboh, marked her retirement in Abuja with a book launch Tuesday titled: Footprints in Time: Dere Awosika.

Speaking at the event, she called on Nigerian leaders and its people to collectively work towards sustaining Nigeria as one indivisible entity in the interest of all.

Also speaking, President Goodluck Jonathan described her as "a woman of great substance." He was represented by the Secretary to the Government of the Federation, Senator Anyim Pius Anyim.

In the book, authored by B.B. Suleiman and Muyiwa Owogbade, Awosika chronicled Nigeria and its current federal structure. She stressed how the 774 local governments and the further division into 9, 555 wards were made for the convenience of governance.

She pledged to donate the proceeds of her book launch to the benevolent and the church.

Awosika, born in Sapele, Delta State, is a graduate of Pharmacy from Ahmadu Bello University, Zaria with an MSc. in Clinical Pharmacy and Ph.d in Pharmacy Technology from University of Bradford, School of Pharmacy, United Kingdom.