Under the new agreement, Animal Planet and Discovery Travel & Adventure will be offered on Cable TV's basic package, while Discovery Health, Discovery Science and Discovery H&L will be carried as part of a premium offering.
Flagship brand, Discovery Channel, has been available exclusively to Cable TV viewers since 1998.
Discovery Asia senior director of integrated marketing Kevin Dickie said that the five new channels were now available on rival networks because there are no exclusivity agreements. "Ultimately, we want as many outlets in the marketplace as we can and if the marketplace allows us to do this, then we will move in that direction," he said.
Dickie also claimed that the sign-up rate for Discovery's channels on Now Broadband TV was better than expected.
"We've been told that 100,000 households - out of PCCW's existing base of 480,000 broadband customers - have registered," he said.
Cable TV executive director Eric Lo said the new channels would give viewers more choice in documentary programming.
"Discovery Channel, which has won wide acclaim from Hong Kong viewers, is one of our most-watched channels. Brands distributed by Discovery Networks are already household names in Hong Kong and I have no doubt the addition of more channels will be welcomed."