The all-share index gained 1.16% to 44,367 points, a level last reached in February 2018.
Dangote Cement rose 6.18% to 275 naira, valuing the cement group at 4.675 trillion naira ($11.29 billion).
The cement maker has said it aims to buy back up to 10% of its share capital in a number of tranches.
Dangote is majority-owned by Africa's richest man Aliko Dangote and the company accounts for a third of the local stock market's value.
Dangote Cement said on Wednesday it will buy back up to 170 million shares, or 1% of its issued shares, over two-days from Jan. 19.
It had bought 40.2 million shares in December 2020 at 243.02 naira, the first tranche of its buyback programme to return cash to shareholders.
The company said it will monitor market conditions in deciding on further tranches of the buyback programme.
($1 = 414.00 naira)
(Reporting by Chijioke Ohuocha; editing by Jason Neely and Jane Merriman)