``A strike on Amtrak would have an adverse effect on the traveling public and would severely hamper rail-freight shipments,'' said Clinton.
Nationwide, he added, such an action would affect some 500,000 rail commuters.
A strike would also affect SEPTA commuter trains dependent on Amtrak Northeast Corridor tracks maintained by BMWE workers.
Threatened SEPTA services would include the R1 Airport Line, R2 Wilmington, R5 Paoli, R6 Cynwyd, R7 Trenton, and the R8 Chestnut Hill West.
The administration announced the decision from Martha's Vineyard, where the first family is on vacation.
BMWE general chairman Jed Dodd said the decision will infringe on the union's right to collective bargaining.
``We believe he has overstepped his authority under the Railway Labor Act by effectively coming to the aid of Amtrak management, and putting our right to strike on hold,'' Dodd said.
But Amtrak praised the move. ``The president's action recognizes the critical role Amtrak's passenger rail operations play in the nation's transportation network and economy, and will keep Amtrak and numerous commuter-agency trains running,'' Amtrak President Tom Downs said.
Under the Railway Labor Act, President Clinton appointed a three-member Presidential Emergency Board of independent labor arbiters to study the dispute.
Creation of the board effectively will postpone any planned strike action through October 21.
The BMWE represents 2,300 Amtrak employees who construct and maintain trackbed, bridges and overhead catenary.
The majority of BMWE's membership is stationed in Amtrak's Northeast Corridor, between Boston and Washington. Some 300 members are in Philadelphia.
Amtrak says it can't agree to the contract the BMWE is proposing because it's a ``freight deal'' - a pact with a wage structure based on what ``profitable freight railroads'' have awarded its workers.
BMWE's Dodd said machine operators in his union currently earn $14.25-$15.94 an hour. That's $3 per hour less than SEPTA pays its machinists, and $5-6 per hour less than the Long Island Railroad pays its workers, contends Dodd.
Amtrak, however, disputes the BMWE claim that its membership is underpaid. It claimed its current BMWE compensation package amounts to approximately $23 an hour, when benefit costs are added to its average $15.58 hourly wage.
The Associated Press contributed to this report.
