The coal industry would have a major [WORD ILLEGIBLE] weapon to control wildcat strikes under an amentdment to the administration's labor law revision bill that was approved yesterday by a Senate subcommittee.

The provision would empower employers to seek injunctions barring wildcat strikes in response to so-called "stranger picketing," under which workers at one facility - or even total outsiders - can and often do close down another facility without union authorization.

This is a common practice in the coalfields, where United Mine Workers members respect lines, authorized or not.

Roving bands of pickets, often moving from state to state and wearing ski masks to hide their identities, were major contributors to the wave of wildcat strikes that crippled the Appalachian coalfields over a 10-week period last summer - at one point idlign up to half the UMW's 160,000 working members.

Unauthorized work stoppages and their impact on both productivity and the financial solvency of UMW benefit funds are at the heart of issues still unresolved in the current UMW coal strike, now in its sixth week.

It was considered unlikely, however, that the legislation would have any impact on negotiations, which are reportedly making some progress here under the auspices of federal mediators.

The original labor law revision bill, which was drafted by the White House and organized labor to expedite union representation elections and punish employers for impeding organizing or bargaining, made no stranger picketing.

The House, in a last-minute amendment added during floor debate on the measure late last year, gave the National Labor Relations Board the power to seek injunctions to curb stranger picketing.

The provision approved yesterday by the Labor Subcommittee of the Senate Human Resources Committee would give that power to employers rather than the NLRB.

The amendment was one of several substantive changes proposed by Human Resources Chairman Harrison A. Williams Jr. (D-N.J.) to overcome criticism that the House-approved bill is anti-business and to ease passage of the measure through the Senate.

In spite of the modification the bill continues to have strong opposition from business groups, and is expected to encounter a filibuster when it reaches the floor. Weakening amendments are expected to be introduced next week when the full Human Resources Committee considers the bill.

Along with the controls on stranger picketing, the subcommittee reduced proposed penalties for thwarting union organizing AFL-CIO representatives said they were "disappointed" by the changes, but indicated they could live with them.