CANNON <CAN> SELLS STAKE IN HBO/CANNON VENTURE Cannon Group Inc said it agreed in principle to sell its 50 pct interest in the HBO/Cannon Video joint venture to the Home Box Office unit of Time Inc <TL>. The company said it is making the sale because in the near future all of its video products will be licensed in the United States and Canada to either the Warner Brothers unit of Warner Communications Inc <WCI>, or to Media Home Entertainment.