EARNINGS : Banks, Thrifts Show Mixed Profit Picture : Reports: First Interstate saw big gains; Ahmanson made headway against problem loans.

The parent company of Home Savings of America posted a 43% gain in first-quarter operating profit Tuesday, but another major California-based thrift holding company, Great Western Financial Corp., said its operating earnings were off 10% from a year earlier.

Onetime gains from changes in income tax accounting methods had boosted the companies’ year-earlier results. So, by comparison, both Great Western and H. F. Ahmanson & Co., the Irwindale-based parent of Home Savings, had sharply lower net profits in the latest quarter.

But in terms of their operations, Ahmanson had more success in paring problem loans from its assets in the latest quarter as the companies struggled to emerge from the severe slump in California real estate.

Among major banks, meanwhile, First Interstate Bancorp said its profit was up fivefold from a year ago, partly because of onetime accounting gains recorded in the latest quarter. Even without those items, First Interstate’s earnings would have doubled. It also hiked its quarterly dividend 10 cents, to 40 cents a share.

Though the results generally met or exceeded Wall Street estimates, the stocks of many banks and other financial institutions tumbled.

A sharp drop in bond prices was cited as the main catalyst “as people became worried again that interest rates might go up” and squeeze bank profits, said Robert Albertson, an analyst with Goldman, Sachs & Co.

Ahmanson, the nation’s largest thrift holding company (with $48.6 billion in assets), said its profit in the first quarter fell 53% to $32.9 million.

A year earlier, when it recorded a $47.7-million special gain from the accounting change, profit was $70.7 million.

In the latest quarter, Ahmanson said, it was hampered by the need to add $94.4 million to its loan-loss reserves and by costs related to efforts to sell foreclosed properties.

Great Western Financial, the Chatsworth-based parent of Great Western Bank, also said it sold considerably more foreclosed properties in the quarter, but its first-quarter profit still dropped 45% to $45.2 million, from $81.6 million. The year-earlier results included a $31-million accounting gain.

Great Western had to add $88 million to its loan-loss reserves in the latest quarter. The company is still suffering from “rising single-family residential delinquencies related to the weakness in the California economy,” Chairman James F. Montgomery said in a statement.

Charlotte Chamberlain, an analyst with Wedbush Morgan Securities, also noted that Great Western’s problem loans climbed to 5.4% of its total assets, from 4.5% a year ago, whereas Ahmanson cut its troubled loans in the latest quarter from 5.1% to 4.5% of total assets.

Los Angeles-based First Interstate said its net income soared to $304 million from $60.6 million a year earlier. The latest earnings included a $200-million accounting gain.

First Interstate also said it continued to reduce its proportion of problem loans and that non-performing assets fell 55% from a year earlier--to $668 million from $1.48 billion. First Interstate’s assets totaled $49 billion at the end of March.

In San Francisco, Wells Fargo said its net income fell to $108 million from $119 million a year earlier, but the latest profit figure still exceeded some analysts’ expectations. The decline was due largely to foreclosure, corporate overhead and marketing costs.