NEW YORK (AP) _ Syndicated TV's ''Return to the Titanic ... Live,'' the unveiling a week ago of artifacts from the sunken luxury liner, drew an estimated one-third of the viewing audience from the networks.

''Titanic'' received a 22.9 rating and a 33 share, according to A.C. Nielsen Co. ratings released Tuesday.

NBC won the week ending Sunday with an average prime-time rating of 15.8. CBS had a 13.4 and ABC a 12.6. NBC's 38-week win streak was snapped the previous week because of the World Series on ABC.

Sunday was the first day of the November sweeps, one of four periods a year when ratings are measured in local markets to set advertising rates. The networks put on special programming to boost ratings.

CBS opened the competition with the first installment of its two-part miniseries ''Echoes in the Darkness,'' based on the Joseph Wambaugh best- seller about a Pennsylvania murder case. It finished 11th with a rating of 20.1 and a 33 share.

The rating is a percentage of the nation's 88.6 million households with televisions. The share is a percentage of households actually watching television during a time period.

NBC's entire Thursday-night lineup made the top 10 network shows, including ''L.A. Law,'' with its highest rating yet, 21.0.

The top 10 were: ''The Cosby Show'' NBC, ''A Different World'' NBC, ''Cheers'' NBC, ''Growing Pains'' ABC, ''Night Court'' NBC, ''Who's the Boss?'' ABC, ''Murder, She Wrote'' CBS, ''60 Minutes'' CBS, ''Family Ties'' NBC and ''L.A. Law'' NBC.

''Titanic'' would have ranked seventh had the list included syndicated programs.

The 10 lowest-rated shows were: ''The Oldest Rookie,'' ''Top Flight'' (a CBS special), ''Hotel,'' ''Sledge Hammer 3/8'' ''The Charmings,'' ''West 57th,'' ''My Sister Sam,'' ''The Midnight Hour,'' ''Everything's Relative'' and ''Leg Work.''

Fox Broadcasting Co. also got off to a good sweeps start with ''21 Jump Street'' getting its highest rating ever, a 6.1 and a 10 share. That would put it ahead of the two lowest-rated network shows in the Nielsen rankings.

The ''CBS Evening News'' has won all six weeks so far in the new season.

For the week that ended Oct. 30, CBS had an average rating of 12.4 and a 22 share. ABC's ''World News Tonight'' had an 11.3 and 20 share and ''NBC Nightly News'' had an 11.1 and 20 share.