Dec 12 (Reuters) - Construction material supplier Texas Industries Inc's owners are exploring a sale of the company and are working with Citigroup to find a buyer, Bloomberg reported on Thursday, citing three people with knowledge of the matter.

The company's shares, which closed at $58.54 on Thursday on the New York Stock Exchange, were up 11 percent in extended trading after the report.

Dallas-based TXI, which has a market valuation of $1.67 billion, may draw interest from U.S. competitor Vulcan Materials Co and Switzerland's Holcim Ltd, the news agency quoted one of the people as saying.

The company's largest shareholders, Southeastern Asset Management and NNS Holding, have been looking to exit their stakes in the company for some time, but may struggle to get a sufficient price, the report said.

Money management firm Southeastern, which with Carl Icahn was involved in a protracted effort to block Michael Dell's $25 billion offer to take Dell private, had a 28 percent stake in TXI as of Sept. 30, according to Thomson Reuters data.

NNS Holding, an investment vehicle for Egyptian billionaire Nassef Sawiris, has a stake of about 23 percent, according to Thomson Reuters data.

Spokespersons for TXI, Southeastern, NNS, Holcim and Vulcan Materials could not be reached for comment outside normal U.S. business hours.

Robert Julavits, a spokesman for Citigroup, declined to comment on the Bloomberg report.