Even as the number of multiple listing services that share listing data continues to grow, members of two of California's biggest MLSs are on the verge of losing access to information about each other's listings in a spat that highlights tensions over efforts to build a statewide MLS. With the blessing of the California Association of Realtors, San Dimas-based California Regional MLS is building a statewide MLS that currently provides services to about 73,000 agents and brokers, making CRMLS the largest MLS in the nation. In January, CRMLS announced that it intends to pull out of California Real Estate Technology Services Inc. (CARETS), a joint venture of six California MLSs that aggregates some 108,000 active listings in 18 counties to one common database. CRMLS CEO Art Carter s...