National Bank of Kuwait  reported flat full-year profits on Thursday, while fourth quarter earnings fell shy of estimates, as the Gulf state's largest lender grappled with what it called a "challenging operating environment."

The lender said net profit was 302.4 million dinars ($1.1 billion) in 2011 compared with 301.7 million in 2010.

Fourth quarter profits stood at 76.8 million, according to Reuters calculations based on previously issued results, down from 77.16 million in the prior-year period.

Analysts had forecast, on average, profit of 77.47 mln dinars, in a Reuters poll. In a statement, NBK Chief Executive Ibrahim Dabdoub said "2011 was another challenging year."

"NBK's strong performance despite the weakening operating environment, the ongoing pressures on the global economy as well as the political unrest in the Middle East is testimony to the success of the bank's conservative strategy and focus on its core banking operations," he said.

Total assets rose 5.6 percent in 2011 to 48.9 billion dinars, while net operating income was up 8.4 percent to 540 million dinars last year. NBK shares were up 1.75 percent on the Kuwait bourse.-Reuters