MCI’s board rejected the sale of its cellular unit.

Mobile Communications Corp. of America and its partner in the proposed purchase, Bellsouth, said they will take unspecified legal action against MCI Communications. The preliminary agreement had called for the two companies to buy all of MCI’s paging and cellular mobile telephone operations for $121.5 million. MCI soured on the deal after learning of Bellsouth’s involvement because a cellular mobile joint venture would allow Bellsouth to offer local phone service outside its region, a move that MCI opposes for former Bell operating companies.