Executives from some of France's biggest companies, including energy giants GDF Suez SA and Alstom SA, are slated to fly to Tehran next month—signaling a fresh wave of corporate interest in Iran as the West eases sanctions.

Details of the high-level business trip are emerging after Iran and Western powers completed the terms of an interim nuclear deal on Sunday, with Tehran agreeing to closer international monitoring of its nuclear program in exchange for limited, temporary sanctions relief. The deal specifically eases restrictions...