WASHINGTON (AP) _ The Securities and Exchange Commission charged a Texas bank holding company Thursday with misstating its earnings in 1984 and 1985, and underestimating its allowance for bad loans in 1984.

The Houston-based company, Texas Commerce Bancshares Inc., consented in an agreement with the SEC to revise its accounting procedures, but neither admitted nor denied the allegations.

The SEC said the holding company understated its allowance for loan losses in 1984 by $28.2 million and overstated its net earnings. In the first quarter of 1985, the company understated its net earnings, the agency said.

At the time of the alleged violations, the holding company - comprised of Texas Commerce Bank National Association, 67 member banks and other non-bank subsidiaries - was one of the nation's 25 largest bank holding companies. Three months ago it merged with a subsidiary of Chemical New York Corp.

The SEC said that as the company acquired banks and expanded its loan business, it failed to hire enough people for an adequate loan review system and consequently failed to catch problem loans from at least 1981 through 1984.

The problem was made worse, the agency said, by the severe downturn in Texas' oil-based economy.

In Houston, Texas Commerce spokesman Mike Cinelli said: ''This settlement with the SEC was reported ... to our shareholders in March of this year. It (arose from) a matter which was first reported to our shareholders more than two years ago.

''The settlement does not involve any penalty or requirement to restate Texas Commerce Bancshares' reported earnings for any period.''