The success of Ali G and Big Brother helped Channel 4 increase turnover by 12% last year.

In a statement accompanying publication of the group's annual report, Channel 4 chairman Vanni Treves said: "Last year was, by any measure, the most successful in Channel 4's history.

"[It] has left us ready and hungry for the challenges ahead."

Chief executive Michael Jackson said Channel 4 "broke through the mundane and formulaic nature of most modern television to capture the public's imagination".

He said Big Brother had been the "media phenomenon of the year" while other programmes including Ali G, Trigger Happy TV and Jam had provided innovative, distinctive television.

Greater creative risk

Group turnover was up 12% to a record �716m.

Channel 4 said its FilmFour channel had performed particularly strongly, doubling turnover to �8.8m.

Operating profit was down 25% to �33.8m due to increased investments in new businesses.

"The benefits of Channel 4's not-for-profit structure have never been clearer," Mr Jackson said.

"Our dividend to viewers is greater creative risk, a higher proportion of income invested back into programmes and services and a far more diverse range of programmes than other commercial broadcasters."

Digital TV competition

Channel 4 said its share of total television viewing in 2000 was up 2% from the year before to 10.5%.

Its share of viewing in multi-channel homes was 0.3% improved at 7.2%.

Mr Jackson said this "outstanding performance" may prove difficult to repeat because the digital TV market was becoming more competitive.

Mr Treves reiterated the channel's opposition to the Conservative Party's plans to privatise it, if elected.

"Privatisation would divert substantial funds... currently invested in programmes into dividends for shareholders so that the channel would never be the same again."

Also on Tuesday, the broadcaster formally launched 4 Ventures - a division including FilmFour and digital entertainment channel E4 that will manage film and other new business operations.

"4 Ventures will allow us to manage these new businesses more aggressively to ensure they open up new sources of revenue," Mr Jackson said.