LONDON -(Dow Jones)- Abu Dhabi-based International Petroleum Investment Co. has added a dollar-denominated, 30-year tranche to its bond offering, one of the banks running the deal said Thursday. IPIC has set initial guidance at 350 basis points over the U.S. Treasurys. The company has also revised down price guidance on its dollar-denominated five-year bond issue to 262.5 basis points over the U.S. Treasurys. This is at the tighter end of initial guidance in the area of 275 basis points over U.S. Treasurys. IPIC has also tightened guidance on the tranche that matures in March 2022 to 312.5 basis points over U.S. Treasurys. Initial price guidance was in the area of 325 basis points over U.S. Treasurys. Barclays PLC, JPMorgan Chase and CO., Natixis, Societe Generale S.A., and Mitsubishi UFJ Financial Group Inc. are the lead mangers on the deal. The issuer is rated Aa by Moody's Investors Service Inc., AA by Standard and Poor's Corp., and AA by Fitch Ratings. -By Sarka Halas, Dow Jones Newswires; +44 (0) 207 842 9236; Sarka.Halasova@dowjones.com