Et tu, steel?

WILLIAM Brock wasn't the only one to speak out against quotas this week. Commerce Secretary Malcolm Baldrige also got into the act. Both officials carried the case against quotas to a House subcommittee that is considering a dubious measure called the Fair Trade in Steel Act of 1984.

The measure, which would restrict steel imports, is opposed by the Reagan administration.

Congress should reject the use of import quotas for steel.

As Mr. Baldrige observed, one effect of steel quotas would be an ''exaggerated increase in the price of domestic steel.''

Surely, the United States needs to ensure the survival of its domestic steel industry - for national security considerations, as well as for industrial needs. But, as many economists point out, if the domestic steel industry is to recover, it will require an industrywide read-justment, including more joint ventures with overseas firms, mergers, some diversification into nonsteel production (to help financially underwrite steel firms), and a modernization of outdated facilities.

Turning to quotas to keep out lower-cost products would merely delay reform within the industry, while pushing up prices for American consumers.