First Security Corp. reported net income of $45.72 million or $3.04 per share for 1990, up 0.7 percent over the $45.39 million, also $3.04 per share, earned in 1989.

Fourth-quarter earnings totaled $7.79 million or 53 cents per share, down 28.6 percent to $3.13 million or 72 cents per share for the same three months a year earlier.Spencer F. Eccles, chairman of the financial services company, said the 1990 results include seven acquisitions in Utah, Idaho, Wyoming and Oregon. The combined acquisitions consisted of $463 million in loans, $713 million in deposits in 126,000 accounts and 24 banking offices.

Eccles said gains in net interest income and earnings from fee-generating activities and other non-interest sources were largely offset by increased provisions to strengthen loan loss reserves as the nation entered a recession.

Non-performing assets, which comprise non-accrual and renegotiated loans and leases as well as other real estate (ORE), totaled $103.69 million at year end, down from a peak during the quarter of $113.36 million. At year end, they were 2.25 percent of loans, leases and ORE. This compares with non-performing assets a year ago of $85.62 million, which equalled 1.98 percent of loans, leases and ORE.

"Our top priority continues to be to improve the overall quality of our assets," Eccles said. "With the growing economic risks and uncertainties attending the current U.S. recession and with the outbreak of war in the Persian Gulf, we believe it only prudent to increase reserves for possible loan losses."

He said the reserve for loan losses was $80.37 million at year end, up 20.8 percent over the $66.52 million set aside for such contingencies at the end of 1989.