Dart Group Corp. made an $834-million offer...

Dart Group Corp. made an $834-million offer to buy Stop & Shop Cos., a New England grocery and discount store chain. The $30-a-share offer came in a letter from Herbert and Robert Haft, who own Dart Group, to Stop & Shop Chairman Avram Goldberg, and was released after the stock market had closed. Stop & Shop’s stock price closed up 12.5 cents a share at $26.125.