Sen. William L. Armstron (R-Colo.) stalled action yesterday on a $6.3 billion urgent supplemental money bill because it contains a $1 billion housing stimulus program opposed by President Reagan.

Armstrong called the measure a "horrible precedent" because it would set up a special mortgage subsidy program to bail out a single industry. He threatened to keep blocking the bill until congressional leaders agree to drop the housing provisions and pledge not to restore them in conference with the House, which has passed a similar provision.

Majority Leader Howard H. Baker Jr. (R-Tenn.) tried early in the day to split off some crucial money provisions and let the housing provisions be taken up separately later. He said the money provisions would support Treasury emplyes who send out Social Security and veterans checks plus other government units that would otherwise have to cease operations or start furloughing employes soon.

But senators on both sides of the aisle as well as House leaders objected, Baker said late in the day, and he had no alternative but to try to pass the bill in one piece despite Armstrong's "filibuster."

Baker distributed a list provided by the Office Management and Budget saying that delays on some of the money in the bill could have these consequences:

* Failure to provide $8 million in rail funds by the first week of June could force the Kansas City Terminal Line into bankruptcy.

* Failure to provide $28.4 million for payments to airlines by the first week of June could threaten bankruptcies and breaks in service for some of the 40 airlines receiving subsidies.

* Failure to provide $2.4 billion for sewage treatment plant construciton would leave 40 states without money and mean the loss of another construction season.

* Failure to provide relatively small amounts of money to a number of federal agencies could force the Commerce Department to furlough 1,000 employes, the Department of Health and Human Services inspector general's office to furlough 930, the Bureau of Labor Statistics, Labor Department's Employment Standards and Employment and Training administrations to furlough all employes, and the Bureau of Alcohol, Tobacco and Firearms to furlough 1,600.