Rio Tinto (rated BBB) and Caltex Australia Limited (BBB+) are the latest corporates to issue bonds offshore. Rio Tinto went to the US s144A market last week to raise US$3.5 billion in two tranches: US$2.0 billion with a five-year term to maturity priced at 752 basis points over US Treasuries; and US$1.5 billion with a ten-year term to maturity priced at 658 bps over US Treasuries.An unusual feature of the bonds' documentation - but not surprisingly so given Rio's high and short term debt burden and the sizeable interest that Chinalco will take in the group, subject to regulatory and shareholder approval - includes a coupon step-up should Rio be downgraded and a change of control put option at 101.Further to our report a couple of weeks back, Caltex Australia is understood to have priced a US$175 million placement in the US Reg D market, on the Thursday before Easter. Again the bonds were issued in two tranches: US$50 million with a five-year term to maturity; and US$125 million with a seven-year term to maturity. Both tranches were reported by Reuters as being priced at 615 bps over US Treasuries.As an aside, Insto reported that Telstra (rated A) was having trouble finalising a $300 million syndicated loan. Apparently bankers who have been approached are finding the suggested pricing of bank bills plus 160 basis points for three years and 200 bps for five years, a little too tight. Admittedly, Telstra is not looking for a large volume of funds and is comparatively well rated but from the credit spreads seen on the few bond issues that have been completed (offshore) by Australian corporates this year, the bankers would appear to be right. The closest 'comparable' funding would be BHP Billiton's (A+) €2.25 billion Eurobond issue, which priced at mid-swaps plus 255 bps for the three-year tranche and 325 bps for the seven-year tranche. To which would need to be added say 60-70 bps for the basis swaps to bring the funding back to an Australian dollar cost.