IT'S ASTOUNDING. Congressional conferees on the trade bill have now pitched out a long list of flagrantly protectionist provisions that the two houses voted into it last year. Many of the worst and most inflammatory favors to special interests are gone. Disburdened of them, the bill suddenly begins to look less disreputable and a little more like a serious attempt to strengthen trade policy.

Until last Tuesday, it had seemed likely that the conference would be a prolonged haggle among the defenders of various industries demanding shelter from foreign competition. Instead Rep. Dan Rostenkowski, in his first offer to the Senate conferees, offered a sweeping list of deletions of protectionist goodies. Two days later the senators under Lloyd Bentsen replied by accepting the House's deletions and going a little further. That was particularly impressive because most of those items had stronger support in the Senate than in the House. By rising to the House's challenge with speed and skill, Sen. Bentsen has greatly improved the possibility that a useful bill will emerge.

But -- a necessary caution -- this process is only at its beginning. Mr. Bentsen and Mr. Rostenkowski have begun their work with the more limited issues; the broader and deeper ones involving dumping and retaliation still lie ahead of them. And this is only one section of the conference on this gigantic bill, although by far the most important one; there are 16 other sections.

All that said, the two chairmen's achievement deserves respect. It sets an influential precedent for the other subconferences, and they have established a momentum toward a final bill that would be a vast improvement over the present versions.

Sen. Bentsen has been pushing for some time for legislation that would impose more consistency on the administration's trade performance, and require the president to give trade greater importance in his decisions. Most of Congress argues that successive presidents have slid into the habit of routinely sacrificing trade to other diplomatic and security interests. That, unlike protection, is a legitimate issue and deserves attention.

Lamb producers who wanted import quotas and the four sugar refiners lobbying for more subsidies will have reason to be pretty sore about the past week's progress. Just about everyone else, but especially people who think that trade is going to be crucial to this country's prosperity, would call it a pretty good week's work.