FIRST OFF . . .

After two straight nights of audience losses, “Amerika” showed a slight increase in ratings for its fourth episode Wednesday. Ratings figures out Thursday showed that ABC’s controversial miniseries was seen in about 15.6 million homes Wednesday--short of 21.5 million on Sunday but up from 15.5 million on Tuesday. Chapter 4 of “Amerika” ran second to NBC’s “Cheers” at 9 p.m. but won from 9:30 to 11 p.m. ABC said the drop-off had been disappointing but “the drama requires an unusual degree of concentration and involvement on the part of the audience, and in that regard, we feel ‘Amerika’ has been an unusual success.” ABC spokesmen said some “Amerika” advertisers had been promised a 30% share of audience for their commercials but most were given no guarantees.