Borland International Inc’s shares plunged 272 pence to 943 pence in London yesterday after news came through that Lotus Development Corp, flushed with the success of its suit against had Paperback Software, had filed suits in Boston against Borland and against Santa Cruz Operation Inc over alleged infringement of its copyright in 1-2-3 by Borland’s Quattro Pro and Santa Cruz’s SCO Professional spreadsheets. Borland anticipated the Lotus suit by filing its own suit seeking declaratory relief – confirmation that Quattro Pro does not infringe any Lotus copyrights. Borland filed the suit in San Jose in part because it wants the spat to be argued out in California rather than in Boston. Lotus is particularly keen to get after Quattro Pro because Borland is offering the $500 product at $100 to people that trade in their 1-2-3 for it. Santa Cruz argues that it has been selling its Unix spreadsheet since 1986 and that Lotus did not launch a Unix 1-2-3 till this year.