CBS tied NBC in the ratings race last week, but it was too little, too late to make a difference in the final standings of the almost completed 1987-'88 television season, it was reported Tuesday.

The season ends Sunday, April 17, and the final order is statistically pre-ordained NBC will win, ABC will be second and for the first time in television ratings history CBS will come in third.For the season-to-date, after 29 weeks NBC maintains its big lead with a 16.1 rating and a 26 share. ABC has a 13.7 rating and a 22 share, while CBS has a 13.5 rating and a 22 share.

For the week ending April 10, NBC and CBS each had a 14.0 rating and a 24 share. ABC was third with an 11.2 rating and a 19 share.

For CBS, the light at the end of the tunnel was that the network appears to be closing the season with an improved ratings performance. It had four of the top 10 shows; NBC had five, four of which were reruns, and ABC one, also a rerun. There were 27 reruns last week on a list of 70 shows, a sure sign of spring.

CBS won Monday, Friday and Sunday nights, with NBC taking Tuesday, Thursday and Saturday and ABC holding onto Wednesday.

NBC won the Sunday movie battle with sexy Raquel Welch in Scandal In A Small Town, which ranked fifth, but CBS thundered right behind with the remake of Red River starring James Arness, which finished in ninth place. ABC's Sunday movie was To Russia with Love, one of Sean Connery's best Bond films, which wound up in 55th place.

CBS also got a ratings boost from its NCAA Basketball Championship on Monday, which ranked seventh in the ratings, and from the fact that its string of new limited run, little-watched comedies were off the air for the season.

This week ABC had undisputed title to the bottom of the ratings list with the bottom four shows. Reading from the bottom up they were Ohara and Supercarrier (tied for 70th), Hotel and Probe.

If CBS entertainment had a good week, CBS News did not, with "ABC World News" with Peter Jennings edging out "CBS Evening News" with Dan Rather for the top spot.

ABC News also scored well with a documentary, Drugs: A Plague Upon the Land, which tied for 50th place. That's good for a news show, and the network received more than 1,000 phone calls about the Jennings-anchored program.

The top 10 prime time shows for the week ending April 10, according to the A.C. Nielsen Co., were: 1. The Cosby Show (NBC); 2. Murder, She Wrote (CBS); 3. My Two Dads (NBC); 4. Cheers (NBC); 5. Scandal In A Small Town (NBC); 6. Golden Girls (NBC); 7. NCAA Basketball (CBS); 8. 60 Minutes (CBS); 9. Red River (CBS); and 10. Who's The Boss? (ABC).