• Applied Terravision Systems Inc. is being purchased by a Canadian subsidiary of The Petroleum Place Inc., Denver, for C$105 million. The transaction depends upon a Petroleum Place's initial public offering. ATS shareholders will receive C$3 worth of Petroleum Place stock for each share of ATS. Petroleum Place will form a new business unit, Energy Enterprise Online, which will include ATS and its Denver-based Paradigm Technologies business. Separately, Halliburton Co.'s Halliburton Energy Services Inc. has acquired a 15% equity position in Petroleum Place for $55.15 million. Halliburton subsidiary Landmark Graphics Corp. will form an alliance with Petroleum Place to provide online access to relevant Landmark software for use in the acquisition and divestiture process, and will participate in joint software development for Internet-based property evaluations. • Western Geophysical, Houston, has launched www.infoSeis.com, a web site that provides interactive access to Western's worldwide 2-D and 3-D multiclient seismic data library. • Midland, Texas-based GeoSpectrum Inc., a provider of technical evaluation services, and Petroleumsite, also of Midland, a provider of online marketing services, have formed a joint venture to provide marketing support services to buyers and sellers of oil and gas properties, drilling prospects and other related assets. • Twelve major oilfield-service firms are forming a joint venture, OFS Portal, that would provide an e-catalog and other service and supply information. The participating firms are ABB, Baker Hughes, BJ Services, Cooper Cameron, Ensco, FMC, Halliburton, National Oilwell, Schlumberger, Smith International, Transocean Sedco Forex and Weatherford. • TransZap Inc., home to Oildex Connect, Denver, has acquired Petrolis.com, Oakland, Calif., whose configurable exchange systems integrate enterprise resource products and Internet and client-server products with legacy standards such as electronic data interchange. Terms were not announced.