New Haven, Connecticut-based Southern New England Telecommunications Corp has definitive agreement to buy cellular properties from Bell Atlantic Corp and Nynex Corp for about $450m in cash: the properties include all of the Rhode Island and the New Bedford, Massachusetts service areas now owned by Bell Atlantic, Nynex’s 80% of the Pittsfield, Massachusetts franchise and a 16.1% stake in a cellular partnership already 82.5% owned by Southern New England, which says that in the wake of the deal, which gives it a big bargaining counter in any talks, it may seek an alliance with a national US wireless consortium.