A Chinese woman adjusts a Chinese national flag next to U.S. national flags before a Strategic Dialogue expanded meeting, part of the U.S.-China Strategic and Economic Dialogue (S&ED) in Beijing Thomson Reuters WASHINGTON (Reuters) - The U.S. Treasury Department is crafting rules that would block firms with at least 25 percent Chinese ownership from buying U.S. companies involved in "industrially significant technology," the Wall Street Journal reported on Sunday.

Citing people familiar with the matter, the newspaper said the plans were not finalized and industry would have a chance to comment before they went into effect. It also said the U.S. National Security Council and Commerce Department were devising plans for "enhanced" export controls to keep such industrially significant technologies from being shipped to China.

The White House, Treasury Department and Commerce Department did not immediately reply to requests for comment.

(Reporting by Arshad Mohammed and Julia Harte; Editing by Peter Cooney)