Worldwide sales of electronics products will reach $413 billion in 1987, with the U.S. share accounting for nearly half the world total, according to an Electronic Industries Assn. forecast. The U.S. industry trade group said that total world sales will be up from $386 billion in 1986 and could reach $500 billion by 1990. U.S. consumption of electronics products totaled $189 billion in 1986 and is expected to rise to $200 billion for all of 1987, the organization said. Japan ranks second, with 1986 sales of $54 billion expected to reach $58.4 billion for 1987.