The US version of Kath & Kim has been thrown a surprise lifeline.

Despite dwindling ratings in its first three weeks and savage reviews, US TV network NBC announced on Friday it was picking up the sitcom for a full season.

The decision will provide a huge cash windfall for the Australian creators of the show, Gina Riley, Jane Turner and Rick McKenna, who are executive producers on the US spin-off.

“Kath & Kim is a show we love and believe in,” NBC executive vice president Teri Weinberg said.

“We have incredible confidence in the creative auspices of this show and we believe it’s a perfect fit with our Thursday-night comedies.”

NBC’s full season order follows a nine per cent rise in ratings for last night’s fourth episode, with 5.4 million viewers.

That was up from a poor 4.99 million tuning in last week, but still well below the better-than-anticipated 7.5 million debut.

The show also performs reasonably well in the key demographic of 18 to 49-year-olds.

The US version stars Molly Shannon and Selma Blair as the feuding mother-daughter duo.

Riley and Turner starred as Kath & Kim in the top-rating original Australian series.