Valley National Corp., parent company of Valley Bank and Trust Co. of Utah, reported net income of $11.0 million or 55 cents per share for the first quarter, up from $607,000 or 3 cents per share for the same period last year.

A gain of $5.8 million, 29 cents per share (net of tax), from the sale of securities is included in the first quarter 1991 net income.During the first quarter, the bank holding company said it began a program to reposition the securities portfolio by disposing of tax-exempt securities. The program has continued into the second quarter and, the company said, will result in about the same gain as the first quarter.

"We are encouraged that the first quarter financial performance continues the positive trend begun in 1990," said Chairman Richard J. Lehmann. "Earnings as well as credit quality have been headed in the right direction, showing improvement during the past year."

Total non-performing assets declined $1.4 million for the quarter. On March 31, non-performing assets were $481.0 million, down from $482.4 million at the end of the previous quarter and $535.8 million a year earlier.

As previously announced, the corporation purchased the remaining 51 percent of the common stock of Western Security Life Insurance Co. (Phoenix) from Lincoln National Corp. (Fort Wayne, Ind.). This acquisition, which did not materially affect first-quarter earnings, resulted in a $6 million increase to the corporation's equity.

At March 31, 1991, total assets of the corporation were $10.3 billion and total deposits were $9.3 billion. The corporation's shareholders' equity was $469.5 million or 4.54 percent of total assets, and the risk-based capital ratio of 7.70 percent exceeded the current regulatory requirement of 7.25 percent.