SYDNEY — In the biggest production commitment in Australian film history, “Star Wars” director George Lucas Wednesday announced the second and third prequels in his 20th Century Fox sci-fi franchise will lense at Rupert Murdoch’s Fox Studios Australia.The second installment will start pre-production in October with photography commencing in April 2000, while the third part will go into production in 2003. With a combined budget of $240 million, the films are expected to effectively take over the six-soundstage News Corp.-owned Sydney facility. The first prequel, “Star Wars: The Phantom Menace,” starring Ewan McGregor, lensed in the U.K. last year and is now in post production in California, where post for the Sydney-filmed installments will also occur. Longed for Down Under At a packed press conference, Lucas said he had long wanted to work in Australia, owing to its similarities to California, price competitiveness and, “primarily,” because of Oz’s pool of film talent. Lucas stressed the bulk of the crew, supporting cast and creative personnel would be Australian, creating “hundreds of jobs,” and he opined it was “inevitable” more mega-budget projects would follow. News Australia topper Lachlan Murdoch said, “The fact that Fox Studios Australia can now bring together some of the genius of LucasFilm and the skill and creativity of the Australian film industry is a dream come true.” FSA, which opened its doors in May, was used for feature films “The Matrix” and “Babe: Pig in the City” as well as “Farscape,” a 13-part Jim Henson TV series currently lensing for CBS.