The company has exercised its call option to buy 22.88 million shares of Vizag Seaport from International Port Services Pvt Ltd., it said in a statement.
International Port Services is the investment arm of U.K.-based Portia Management Services Ltd, which is Gammon's joint venture partner in Vizag.
Vizag Seaport, which has two bulk handling terminals at Visakhapatnam port has also allotted 8 million shares to Gammon's subsidiary Cochin Bridge Infrastructure Co. Ltd, it added.
Shares in Gammon Infrastructure were trading up 0.46 percent at 163.75 rupees in a firm Mumbai market.