WASHINGTON—The House of Representatives is expected to approve legislation Thursday to tighten insider-trading rules in Congress, despite changes made by a top lawmaker to remove a key disclosure provision.

Rep. Eric Cantor, the No. 2 House Republican, plans to bring his version of the Stop Trading on Congressional Knowledge Act, or Stock Act, to the floor of the GOP-controlled chamber on Thursday, using a procedure that will prevent lawmakers from voting on major amendments. It is expected to pass by a wide margin.

House...