The move of hit-music master Dick Clark from one syndicated countdown show to another has caused some shifting in the local countdown lineup.

Clark debuts Sunday as the host of "Countdown America" on WAVA-FM (105.1) from 8 a.m. to noon. Clark had been under contract to Mutual Radio Network since 1981, but left when he became principal owner of United Stations Radio Networks, his new base. Now WCLY-FM (95.5) will carry Mutual's "National Music Survey," with new host Bill St. James, from 8 to 11 a.m. Sunday.

That leaves WLTT-FM (94.7) without a countdown show -- by choice. "We thought the show without Dick Clark was like the Johnny Carson show without Carson," says Bob Hughes, program director at WLTT. The station will feature its normal mix of "light rock" for Sunday mornings.

The countdown form has become increasingly popular with younger disc jockeys over the last two years, giving some competition to stalwarts Clark and Casey Kasem. "A couple of years back people discovered Top 40 really worked," says Joel Denver of Radio & Records, an industry publication. "These shows are popular because of the authoritative manner in which they present the music," says Smokey Rivers, program director at contemporary hit WAVA. "The hosts provide news and insights into the lives of people. They have research staff behind them and so they get intriguing facts." Gary Balaban, acting program director of country music WMZQ-FM (98.7), says the public simply "loves to hear the hits. And in a short period of time, these shows concentrate all these new songs. It may be that you don't want to hear those songs every day."

WHUR-FM (96.3) recently dropped its in-house countdown show because it was difficult to do a local survey and the show lacked the intimacy of celebrity interviews, says program director Jesse Fax; the urban station now carries a syndicated show on Saturdays. WRQX-FM (107.3) has two syndicated countdowns, including Kasem's, as well as its own top 10 each night at 10. "Some people say the countdowns are popular because it is orderly and structured and people are missing that. I don't know if it goes that deep," says Randy Lane, program director.

To inaugurate the Mutual countdown, which also features a three-minute segment with Mike Love of the Beach Boys, Classy 95 program director Allan Hotlen announced that at 1 p.m. tomorrow the station will play the songs its listeners rank 100 to 31 from the last 10 years. St. James will pick up Sunday with the top 30.

For the countdown conscious, other shows include:

*"Les Carpenter's Spotlight at Noon," on Friday with Carpenter playing the top seven songs of a particular year on WWRC-AM (980).

*"Coast to Coast Top 20," with Doug Steele on WHUR, Saturday, 8 to 10 a.m.

*"Scott Shannon Rock in America," on WBMW-FM (106.7), Sunday, 9 a.m. to noon.

*"The Weekly Country Music Countdown," with Chris Charles on WPKX-FM (105.9), Sunday, 10 a.m. to noon.

*"American Top 40," with Casey Kasem on WRQX, Sunday, 10 a.m. to 2 p.m.

*"Your Hit Parade," with Bea Wain and Andre' Baruch on WWRC, Sunday, noon to 1 p.m.

*"American Country Countdown," with Bob Kingsley on WMZQ, Sunday, noon to 3 p.m.

*"Rick Dees' Weekly Top 40," with Dees on WRQX, Sunday, 7 to 11 p.m.

*"The Countdown," with Walt Love on WKYS-FM (93.9), Sunday, midnight to 2 a.m. Special Reports

Beginning tonight at 9, WWDC-FM (101.1) is running a weekly two-hour "Best of Greaseman" . . . Audrey Chapman, a family therapist whose Thursday morning call-in segment was dropped from WHUR's lineup, is now hosting her call-in show two Sundays a month. The topic this Sunday at 2 p.m: "Diets and Body Image" . . . The well-sneakered Larry Matthews of WMAL-AM (630) intends to run the first seven miles of the Marine Corps Marathon, which begins at 9 a.m. Sunday, interview participants and follow their progress to the finish line. Meanwhile in the studio Ed Walker will be talking to band leader Art Mooney from 9 to 9:30 a.m. . . . Radio Smithsonian has put together a comprehensive look at Halley's comet that will air on WGMS-FM/AM (103.5/570) Sunday at 9 p.m. The host and producer is Jesse Boggs, and the interviewees will include Fred Whipple, director emeritus of the Smithsonian Astrophysical Observatory at Harvard . . . Lisa Simeone of WETA-FM (90.9) will host "Virtuosi: Fritz Kreisler," a look at the career of the master violinist Monday at 10 p.m. Don Lee produced the broadcast. Briefs

WWDC-AM (1260) will be carrying Georgetown University basketball starting Thursday at 7 p.m. . . . Karen Leggett of WMAL won the Maryland State Teachers' Association School Bell Award recently for her five-part series, "Education: 2001, Hungry to Learn" . . . WLTT has awarded $6,100 in grants to the Whitman-Walker Clinic, the Montgomery Hospice Society and the Calvary Shelter in its quarterly distribution of its Good-Lite Fund monies . . .