FMC CORP <FMC> IN PEROXIDE VENTURE FMC Corp said it has entered into an equally owned joint venture with Indo-Thai Synthetics called Thai Peroxide Co Ltd to build a hydrogen peroxide plant with an initial capacity of 5,000 metric tonnes of 100 pct peroxide north of Bangkok. The company said the plant is expected to starft operating by the fourth quarter of 1988. It said the venture received grants and incentives from the government of Thailand.