(Adds comment on rail asset)
By Alberto Alerigi
SAO PAULO, July 13 (Reuters) - Brazilian steelmaker Companhia Siderurgica Nacional S.A. is looking to sell under-performing assets this year in an attempt to reduce debt during a steel and iron ore slump, Chief Executive Officer Benjamin Steinbruch said on Monday.
Speaking on the sidelines of a steel conference in São Paulo, Steinbruch, whose family is the company's majority shareholder, said that a stake CSN owns in smaller steel rival Usiminas was among the assets the company was potentially looking to sell.
Asked about the 27.5 percent stake CSN owns in rail operator MRS Logistica, Steinbruch said that any sale would only involve a "surplus" share in the operator, and not the whole stake.
"We have to take into account a reality of high interest rates and have to be careful with our debt levels," Steinbruch said.
Reporting by Alberto Alerigi Jr; Writing by Stephen Eisenhammer; Editing by Dan Grebler