J. Curtis Counts, head of the trucking industry's bargaining group, said yesterday the administration's anti-inflation program includes a major loophole through which employers and unions can escape the new 7 percent wage increase guideline.

The program permits wages to rise more than 7 percent next year "if they reflect explicit changes inwork rules and practices that result in demonstrable improvements in productivity of equal or greater value."

While administration officials say they will be strict in demanding positive proof of productivity gains, Counts, the president of Trucking Management Inc., was skeptical yesterday in a briefing for reporters.

"If you really want the means to get around the guidelines, this is the best I can think of," said Counts, nothing that management as well as union bargainers can probably come up with justifications to warrant a productivity exemption if they want to.

Counts, whose industry group will exchange initial proposals for a new master freight agreement with the Teamsters in December, also said it will be difficult, but not necessarily impossible, to maintain the existing level of health, pension and other benefits within the 7 percent guideline. He said, however, he feared some small companies would go "belly-up" if the administration refuses to allow rate increases commensurate with additional labor costs.