The planned $18 billion merger of Time Inc. and Warner Communications Inc. has put other media companies in the limelight as analysts predicted a continued drive to create global communications and entertainment giants.

Stock prices soared Monday amid the merger speculation, with CBS Inc. the biggest gainer. Its shares rose $6 to close at $172.121/2 on the New York Stock exchange. Gulf and Western Corp., owner of Paramount Pictures Corp., rose $2.50 to $45.871/2, and Walt Disney Co. rose $1.121/2 to $77.621/2.Analysts said they expected more consolidations in the industry, although not as big as the deal announced Saturday to create Time Warner Inc.

"It's a unique opportunity and I can't see that you're able to replicate it," said John Reidy, an analyst with Drexel Burnham Lambert Inc.

Time and Warner said the new company would have projected annual revenues of $10 billion - surpassing the current world communications leader, West Germany's Bertelsmann AG, which reported $6 billion in 1987 revenue.

Warner Chairman Steven Ross said in an interview that the merger's greatest impact would be an expansion of Time and Warner's overseas operations. He said the linkup would give Warner better access to foreign markets for its video business.

"We believe that by the mid-1990s the media and entertainment industry will be composed of a limited number of global giants," Time Chairman J. Richard Munro told securities analysts. "Time intends to be one of these companies."