Twitter Inc said on Friday the waiting period under the HSR Act for Elon Musk's $44-billion acquisition of the social media firm has expired.

Completion of the deal is now subject to remaining customary closing conditions, including approval by Twitter stockholders and the receipt of applicable regulatory approvals, Twitter said.

The HSR Act, or the Hart-Scott-Rodino Antitrust Improvements Act of 1976, requires parties to report large transactions to both the Federal Trade Commission and the U.S. Department of Justice Antitrust Division for review.

(Reporting by Nivedita Balu in Bengaluru; Editing by Shounak Dasgupta)