11. Is there a ban on donations from corporations with partial government ownership to political parties?

"No association, other than a political party, shall canvass for votes for any candidate at any election or contribute to the funds of any political party or to the election expenses of any candidate at an election." 
Section 221, Constitution of the Federal Republic of Nigeria 1999 as amended.  

"A company shall not have or exercise power either directly or indirectly to make a donation or gift of any of its property or funds to a political party or political association, or for any political purpose, and if any company, in breach of this subsection makes any donation or gift of its property to a political party or political association, or for any political purpose, the officers in default and any member who voted for the breach shall be jointly and severally liable to refund to the company the sum or value of the donation or gift and in addition, every such officer or member commits an offence and is liable to a fine equal to the amount or value of the donation or gift." 
Section 43 (2) of the Companies and Allied Matters Act.

Section 221 of the 1999 Constitution of the Federal Republic of Nigeria as amended applies to them and if they are registered as companies under the Companies and Allied Matters Act, section 43 (2) of CAMA will also apply to them.