First Security Corp. reports first-quarter 1989 net income of $9.46 million, its strongest quarterly earnings performance since fourth quarter 1982 and a 17.6 percent increase over the same period last year.

Earnings per common share were 73 cents, a 15.9 percent increase over the 63 cents per share reported for first quarter 1988.First Security Chairman Spencer F. Eccles attributes the increase primarily to good loan volume coupled with improved net interest margins. During the first quarter, average net interest margin rose to 4.77 percent, compared with the 4.72 percent in first quarter last year, Eccles said.

First Security's subsidiaries made 25,153 loans in the first quarter, compared with the 24,715 loans made during the first three months of 1988. The 1989 first quarter figures include 2,583 commercial loans for $379.52 million; 21,705 consumer installment loans for $210.43 million; and 865 real estate loans for $119.41 million.

Total loans and leases held by the corporation's subsidiaries at the close of first quarter 1989 were $3.64 billion, up $231.15 million or 6.8 percent from loans and leases held at the end of first quarter 1988.

"Our continued achievements in cost containment, plus the effective and ongoing reduction of our non-performing assets, also contributed to the strong quarterly performance," said Eccles.

He noted that at quarter's end, First Security's non-performing assets had been reduced to $89.76 million, a decline of $19.52 million or 17.9 percent below the $109.28 million in non-performing assets reported at the end of first quarter 1988, and $4.96 million below year-end 1988.

First Security's non-performing assets now represent 2.39 percent of total loans, leases and other real estate, and l.72 percent of total assets, their lowest level in more than five years, Eccles stressed.

Other significant first quarter operational results cited by Eccles included:

- Total assets amounted to $5.23 billion, an increase of $341.29 million over 1988's first quarter.

- Total deposits held by the corporation's subsidiaries at the close of first quarter 1989 were $3.88 billion, up $168.22 million from the deposits held on March 31, 1988.

- Reserves for losses on loans and ORE were $68.48 million at quarter's end. The ratio of loan reserves to total loans and leases was a solid 1.59 percent, compared with 1.82 percent as of March 31, 1988, and equaled 148 percent of non-performing loans and leases.