BBC Expands World News Coverage : Television: The venture is characterized by broadcast insiders as a challenge to CNN.

ANAHEIM —  The BBC’s role in the 21st Century will be determined by the success of its new World Service Television venture, the British network’s chief executive says.

Sir Michael Checkland, director-general of the British Broadcasting Corp., said the network intends to run its television news programs on every continent, including North America, by the end of 1993.

“It’s the most significant thing that we’re doing at the moment, far more significant than what we’re doing (in British domestic programming),” Checkland said in an interview, after reporting that BBC television service to Africa was to begin Thursday.

Checkland described the television venture, which began last year with service to some nations in continental Europe, Asia and the Middle East, as an outgrowth of the BBC World Service. The BBC’s 60-year-old short-wave radio network currently reaches an estimated 120 million listeners worldwide, many of whom consider the London-based service more reliable than their own national media.

Within the broadcast industry, the BBC venture is being characterized as a challenge to Cable News Network, which has been aggressively seeking foreign outlets for its news broadcasts. The Atlanta-based CNN saw its international profile soar with its dramatic coverage of the Persian Gulf War, the fall of the Soviet bloc and other events of interest to global audiences.

Last week, CNN expanded its potential viewership in Europe from 14 million to 22 million by leasing a transponder on the Astra 1b satellite. As if to nudge the BBC, which dominates broadcasting within the United Kingdom, the move brought CNN to some 3 million homes in Britain.

Other television broadcasters, including Capital Cities/ABC and Rupert Murdoch, owner of the American Fox network and Britain’s Sky Channel, are said to be considering expanding into the world news market, but have yet to announce any plans.

Checkland, who Wednesday addressed the World Affairs Council of Orange County, downplayed any competition with CNN. He praised CNN founder Ted Turner as “the global village’s first citizen,” and argued that the American and British networks would bring different slants to their coverage.

“CNN’s strength is the strength of America,” he said. “It’s a window for the world on the most powerful and influential country on the planet, as well as a look at the rest of the world through that country’s window.

“The BBC’s strength is the range and depth of its coverage and its international tradition,” he said, a reference to the British network’s reputation with foreign audiences for impartiality.