Adds share move and details throughout

July 23 (Reuters) - Union Pacific UNP.N reported a rise in second-quarter profit on Thursday, as higher fuel surcharge revenue and core pricing gains more than offset increased operating costs.

Shares of the company were up 1% in premarket trading.

U.S. railroads have capitalized on pricing strength and operational discipline, while efforts to improve network reliability and on-time performance have helped support freight volumes and attract new business.

The West Coast railroad operator's second-quarter net income was up 6.6% to $2 billion, or $3.36 per share, from $1.9 billion, or $3.15 per share, a year earlier.