Bermuda-based Nabors Industries Ltd. has announced that the waiting period for the proposed acquisition of Superior Well Services Inc. under the Hart-Scott-Rodino Antitrust Improvements Act of 1976 has expired without a request for additional information from the US Department of Justice or the Federal Trade Commission.

The largest onshore petroleum driller announced its plans to purchase Superior Well Services for $735.6 million in cash, adding pumps and services used to free oil and natural gas from rock last month.

The transaction remains subject to the results of the outstanding offer to purchase, dated August 11, 2010, which is scheduled to run out on Wednesday September 8, 2010.

As previously announced, holders of approximately 34 percent of Superior Well Services' outstanding shares of common stock have entered into agreements to tender their shares.