Stocks of Ranbaxy climbed 3.46 per cent to Rs 728 -- its one-year peak on the BSE.
Sun Pharma rose by 2.84 per cent to touch its 52-week high of Rs 942.
"The US Federal Trade Commission (FTC) has completed its review of the proposed acquisition of Ranbaxy by Sun Pharma and has granted early termination of the waiting period under the Hart-Scott-Rodino Antitrust Improvements Act of 1976 (HSR Act)," Sun Pharmaceutical Industries and Ranbaxy Laboratories said in a joint statement.
