Calling a truce in a long and bitter battle, timber executives and environmentalists united Wednesday in supporting legislation to codify and expand current protections for old-growth forests on federal land in eastern Oregon.

After nearly eight months of talks, representatives of both groups joined Senator Ron Wyden, Democrat of Oregon, at a news conference in Washington as he introduced a bill that would ban cutting of trees more than 21 inches in diameter and protect delicate watershed areas.

Such prohibitions are already in place in many forests but are administrative in nature rather than mandated by law, and subject to rollback at any time.

In return for their support for such limits, which they had previously fought, timber groups were promised steady, unimpeded access to younger trees as part of a broader program to assure the health of the forests and fire prevention.