City centre leaders have welcomed news that a third series of hit Inspector Morse spin-off Lewis will be filmed this summer.

Bosses at ITV were so pleased with viewing figures for four episodes screened earlier this year - each got about eight million - they have commissioned four more.

Business leaders hope the show will offer a boost to the city's economy as fans flock to the dreaming spires after tuning in.

The pilot episode of the programme was shown in January 2006, winning 11.4 million viewers - and since then programme makers have never looked back.

Kevin Whately, as Lewis, and Laurence Fox, as DS Hathaway, have now developed a strong on-screen relationship, which is becoming as popular as Mr Whately's partnership with John Thaw, who played Inspector Morse.

Lisa Vanoli, a spokesman for ITV drama, said: "When you consider the emergence of digital channels, and the more fractured TV audience you have today, the viewing figures for these two-hour dramas have been extremely good.

"The actors have just finished the read-through for the first episode, but we will not start filming in Oxford until the second week of July.

"We will be filming in Oxford for four weeks in total - one week per each episode. The first episode being filmed is called Allegory of Love and is written by Stephen Churchett, who wrote the pilot episode.

"Chris Burt is back as producer and there are lots of familiar faces in the production team."

Oliver Odell, chief executive of Oxford's city centre management company OX1, and OFVM Film Oxford, which trains Oxford filmmakers, are planning to employ a dedicated film officer to attract more production companies to the city.

Mr Odell said: "The Lewis series must be worth millions to Oxford, because the viewers come to the city to visit the locations.

"If the rights of the series are sold around the world like Morse, then the city is being advertised.

"Oxford is a fantastic resource and we are trying to build a friendly relationship with location managers."

Ms Vanoli said filming would finish in November and the four episodes would be screened early in 2009.

"We are hoping that there will be a number of well-known faces in the new episodes as guest stars and we will be able to confirm their names at a later date," she added.

Producer Chris Burt said: "We are all looking forward to returning to Oxford - the locations always look stunning."

John Thaw, who played Inspector Morse, died of cancer in February, 2002, two years after the last episode, The Remorseful Day, was screened.