WHOLESALE CHANGES DUE IN ABC PROGRAMMING

ABC, which fell to third place in the prime-time ratings race this season for the first time in a decade, said Monday it will replace more than one-third of the schedule next fall with 10 new series, including a spinoff of “Dynasty” and a show that rival NBC had dropped last week--the comedy “Diff’rent Strokes.”

Among the shows canceled by ABC were the 3-year-old private detective show “Matt Houston,” the 2-year-old police drama “T.J. Hooker” and “Three’s a Crowd,” the first-year comedy that starred John Ritter in the role he previously had played on “Three’s Company.”

Only three of the 18 series that ABC introduced this season--”Who’s the Boss?,” “Moonlighting” and “Mr. Belvedere”--were renewed for fall. Among the cancellations were “Finder of Lost Loves,” “MacGruder and Loud,” “Off the Rack,” “Hail to the Chief,” “Wildside,” “Eye to Eye” and “Me and Mom.”

Prior ABC casualties this season were “Call to Glory,” “Jessie,” “Paper Dolls,” “Glitter,” “Hawaiian Heat,” “Street Hawk,” “People Do the Craziest Things” and “Foul-Ups, Bleeps and Blunders.”

In their place for the 1985-86 TV season will be four new comedies, three action-adventure shows and three family dramas, including the spinoff of ABC’s most successful series this season, “Dynasty.” Among the stars of the new shows are Robert Wagner, Kevin Hooks and Eli Wallach.

Reflecting the seriousness of its 10% decline in prime-time ratings this season, ABC is replacing eight hours in its weekly lineup of 22 hours. Four nights will begin with new 8 p.m. programs and only one night will be identical to this season: Monday, with “Hardcastle & McCormick” and “Monday Night Football.”

By contrast, second-place NBC, in moving out of the cellar for the first time in 10 years, is adding only four hours of new programs (six shows) to its fall lineup and is returning three nights intact (Monday, Tuesday and Thursday). CBS, which won the prime-time ratings race for the sixth year in a row, is scheduled to release its fall lineup Friday.

In addition to borrowing from itself with “Dynasty II: The Colbys,” ABC also appeared to be indebted to NBC for three of its other new shows. The most obvious is “Diff’rent Strokes,” which had been a staple on NBC for 6 1/2 years until the network decided to drop it from the fall schedule it unveiled last week. The series ranked 43rd among the 96 series that the networks showed this season.

Brandon Tartikoff, president of NBC’s entertainment division, explained at the time that NBC had begun thinking about replacing the show after Gary Coleman, its 17-year-old star, had said he didn’t want to continue. He subsequently changed his mind, but by then NBC was already thinking of replacement possibilities and, believing the show’s popularity had peaked, went ahead with its plans.

Embassy Television, which produces the series, then went to the other networks to try to elicit interest in picking up the show, as has happened occasionally with other series in the past--most recently in 1982, when NBC revived “Taxi” after ABC had canceled it.

In announcing that “Diff’rent Strokes” would move to ABC in the fall--where it will challenge NBC’s “The A-Team” on Tuesday nights--Lewis Erlicht, president of the entertainment division, praised the series for its “consistent all-family appeal, most especially with young viewers. This past season, the series averaged more than a 40 share among children and teen-agers, demonstrating its continuing strength as an early-evening entry.”

Two other ABC shows seem directly patterned after two of NBC’s popular new series, “The Cosby Show” and “Miami Vice.”

One, “Growing Pains,” is a comedy about a married couple with three children. The wife has recently gone back to work and the husband, a psychiatrist, works out of their home so he can keep an eye on the kids. Former talk show host Alan Thicke portrays the father and Joanna Kerns stars as the mother.

The other, “Hollywood Beat,” stars Jack Scalia and Jay Acovone in what ABC described as a “hip, pulsating drama about two colorful undercover detectives.” It is from Aaron Spelling Productions.

Also joining the ABC lineup next season will be:

--”He’s the Mayor,” a comedy in which Kevin Hooks plays a 25-year-old man who decides on a lark to run for the top job in his home town and unexpectedly wins. His efforts to perform effectively are helped and hindered by a variety of characters around him, including the police chief, a devious councilman, his chauffeur and his father, who is the city’s chief maintenance man.

--”Mr. Sunshine,” a comedy about a cynical English professor (Jeffrey Tambor) whose bitterness and sarcasm stem from having lost his sight and then his marriage. Trying to cheer him up are his 14-year-old son (John P. Navin Jr.), his landlady (Barbara Babcock), his secretary (Nan Martin) and his teaching assistant (Brian Edward Benben).

--”Dynasty II: The Colbys,” a soap opera in which Jeff Colby of “Dynasty” (played by John James), will meet up with his Southern California kin, who are described by ABC as “rich but responsible, powerful yet passionate, manipulative but loving.” Emma Samms also will star as Jeff’s love interest, Fallon Carrington. The same production team responsible for “Dynasty” will oversee the spinoff, which is slated to air Thursdays at 9 p.m., with “Dynasty” continuing on Wednesdays at 9 p.m.

--”J.G. Culver,” marking the return of Robert Wagner to series TV. The former star of “Hart to Hart,” “Switch” and “It Takes a Thief” is cast here as an insurance investigator who divides his time between case work and his Virginia farm, where he lives with his father (Lew Ayres) and two daughters. His partner in the investigations is an Englishman played by John Standing.

--”Family Honor” is a drama about the flip sides of the law in New York City. On the top side is the family of the chief of police (Kenneth McMillan), whose son and granddaughter are on the force; on the underside is the family that runs organized crime (headed by Eli Wallach). Their lives, interrelated already through action on the street and in the courtroom, become more entangled when the granddaughter of the cop family (Daphne Ashbrook) falls in love with the son of the crime family (Michael Woods).

--”MacGyver,” an action-adventure show about a daring adventurer (Richard Dean Anderson) who tackles seemingly impossible rescue missions.

--”The Insiders,” another action-adventure show about two journalists who often work undercover to dig up information for their stories and, as ABC tells it, “are men of the ‘80s, who have commitment, style and energy.” Nicholas Campbell portrays the formally trained reporter; Stoney Jackson plays his street-wise collaborator, an ex-convict.

ABC also said it had ordered three other pilots as midseason replacement series: “Spenser: For Hire,” a private detective show starring Robert Urich; “Shadow Chasers,” a lighthearted action show about two men (Dennis Dugan, Trevor Eve) who investigate reports of parapsychological phenomena, including ghosts, and “Lady Blue,” about a woman cop (Jamie Rose).

Here is ABC’s night-by-night lineup for the fall:

Monday: “Hardcastle & McCormick,” “Monday Night Football.”

Tuesday: “Diff’rent Strokes,” “He’s the Mayor,” “Who’s the Boss?,” “Growing Pains,” “Moonlighting.”

Wednesday: “The Insiders,” “Dynasty,” “Hotel.”

Thursday: “The Fall Guy,” “Dynasty II: The Colbys,” “20/20.”

Friday: “Webster,” “Mr. Belvedere,” “Benson,” “Mr. Sunshine,” “Family Honor.”

Saturday: “Hollywood Beat,” “J.G. Culver,” “The Love Boat.”

Sunday: “Ripley’s Believe It Or Not,” “MacGyver,” “The ABC Sunday Night Movie.”