(Adds details on potential retail asset sale, margins)
Aug 28 (Reuters) - Oil refiner Caltex Australia CTX.AX on Tuesday said it was considering selling certain convenience retail assets it valued at about A$2 billion ($1.5 billion), as higher costs kept its first-half profit at the low end of its guidance.
The company said it was exploring a potential real-estate partnership which could include the sale of 12 percent to 25 percent of its existing freehold site portfolio, with Caltex retaining between 25 percent and 50 percent.
The company's branded convenience stores include names like Star Mart and Woolworths. In July, Caltex said Woolworths WOW.AX would start a wholesale food supply to over 700 existing Caltex convenience sites as part of a 15-year fuel supply deal. primarily deals in the purchase, refining and supply of petroleum products as well as the operation of convenience stores throughout Australia.
It said net profit on a 'replacement cost' basis came in at A$296 million ($217 million) for the six months to June 30, up from A$294 million in the previous corresponding period, as margins were hurt by higher crude prices and corporate costs.
The company in June had forecast half-year underlying profit between A$295 million and A$315 million.
The company's retail earnings also declined 14 percent, impacted by ongoing store transitions.
Brent crude LCOc1 prices have surged about 14 percent so far this year. Caltex's solitary oil refinery, the Lytton refinery in Brisbane, also suffered lower refining margins, down 18.6 percent.
The company said it would pay A$0.57 per share as an interim dividend, down from A$0.60 per share for the first half of 2017.
($1 = 1.3669 Australian dollars)