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

Paragraph 441c (a), United States Code, Title 2, The Congress. 

It is prohibited for any person who enters into any contract with the United States or any department or agency thereof, entailing the provision of goods and/or services to the federal government to make any contribution to any political party, committee or candidate in connection with a federal election.

GRECO (2011), Evaluation Report on the United States of America Transparency of Party Funding (Theme II), p.14