HONG KONG — When the United States government punished ZTE of China this month, saying it had done business with Iran, it released internal company documents that it said detailed how the electronic equipment maker had done it — and that also suggested the problem might not be limited to one Chinese company.

One document described how ZTE would set up seemingly independent companies — called “cut-off companies” — that would sign the deals in other countries. That could enable it to continue to do business in Iran, North Korea and other countries placed under American restrictions.

In describing the effort, the document cited as a model — and at times a cautionary tale — a rival company it called F7. ZTE said F7 had done something similar, though its business in restricted companies ended up hurting its American ambitions.

The document does not give F7’s real name. But the description offered by ZTE matches a company far larger and more politically sensitive: Huawei Technologies, its chief rival and a major force in the technology world.