London Film Festival to Open With ‘Parenthood’ : Movies: With 170 productions from more than 40 countries on its schedule, this festival is the largest in the event’s 33-year history.

“Parenthood,” one of the hit movies of the summer in the United States, will open the 33rd London Film Festival this month. Organizers say it is the biggest-ever film festival here.

The closing-night film will be Italian director Ettore Scola’s “What Time Is It?” whose stars, Marcello Mastroianni and Massimo Troisi, won best actor prizes at the Venice Film Festival this year.

The London festival opens Friday and will run through Nov. 26. It will feature 170 films from more than 40 countries. The first London festival had 15 films; the number for 1987 was about 140.

“If there are good films, they should be screened, and this is a good year,” Festival Director Sheila Whitaker said. “I hope we’ve made sensible choices.”

Besides “Parenthood,” which was directed by Ron Howard and stars Steve Martin, other mainstream American films to have their British premieres at the festival are Rob Reiner’s “When Harry Met Sally. . . ,” starring Meg Ryan and Billy Crystal; “Field of Dreams,” Phil Alden Robinson’s movie about baseball, starring Kevin Costner; and “Earth Girls Are Easy,” with Geena Davis.

Also featured will be “A Dry White Season,” Euzhan Palcy’s film about apartheid, with Marlon Brando; “The Fabulous Baker Boys,” starring Michelle Pfeiffer and Jeff and Beau Bridges; and “Casualties of War” and “Back to the Future II,” both starring Michael J. Fox.

Twenty-three independent American films will be screened at the festival, and there will be a seminar on the topic, “America, the State of the Independents (How Low Can You Get?),” organized by the Assn. of Independent Producers.

The independent films include “Let’s Get Lost,” Bruce Weber’s film about jazz musician Chet Baker, and “James Baldwin: The Price of the Ticket,” about the late writer and activist.

Among the 18 British films to be screened is “Venus Peter”--much-traveled on the festival circuit--with David Hayman and the late Ray McAnally. The film, which marks the directing debut of Ian Sellar, is set in the Orkney Islands off Scotland in the late 1940s.

A strong French contingent includes Bertrand Blier’s “Trop Belle Pour Toi!” (“Too Beautiful for You!”), the opening-night film at the New York Film Festival this fall, and Coline Serreau’s “Romuald and Juliette.”

There are three films from South Africa, two of which--”The Stick” and “Quest for Love”-- have been banned in that country. The third, “Jobman,” is receiving its first screening outside South Africa.

Africa is elsewhere represented with feature films from Algeria, Burkina Faso, Ghana, Guinea Bissau and the Ivory Coast, and the Asian offerings are dominated by “A City of Sadness,” from Taiwanese director Hou Hsiao-Hsien. The film won the Golden Lion at the Venice Film Festival last month.

Among celebrities expected to attend are Ron Howard and French actress Fanny Ardant, who stars with Jeremy Irons in “Australia,” which will also be screened.