Even though ratings for "Conan" have tumbled by about 60% since the show’s TBS debut last year, the network plans to increase spending in a move to protect its investment, reports The Wall Street Journal. (Please note that the WSJ is behind a paywall, and not all readers may be able to access the story.)

"Conan’s” audience has dropped from an average of about 2.4 million in the show’s first month on TBS to about 958,000 viewers in July, the piece adds.

TBS hired Conan O’Brien for more than $12 million per year in 2010, but viewership among 18- to 49-year-olds has declined 11% at the network this past year despite the addition of “Conan,” the story points out.

In the demo that O’Brien has always particularly targeted–18 to 34 year olds–the fall-off for TBS overall has been about the same: 10.8% over the same time frame.

The Time Warner-owned network is fighting back by buying additional costly programming: TBS will start airing repeats of "The Big Bang Theory" as a lead-in to "Conan" two nights per week, at a reported cost of $2 million per episode, the piece points out.

The network is also developing new content to complement "Conan," including "The Wedding Band," about friends who perform music at weddings, the story notes.

The article adds, "TBS said that Mr. O’Brien continues to attract advertisers because he draws young viewers. According to TBS, the median age of his audience—32 years old—remains the youngest among the late-night talk shows. TBS also said that many of his viewers watch the show online, and don’t register in television ratings. His video segments and episodes on his website, teamcoco.com, surpass more than 1 million views each week."

As previously reported, TBS pulled the plug on "Lopez Tonight," which had been the lead-out for "Conan," earlier this month. "Lopez Tonight" suffered from poor ratings and a lack of profitability, the story notes, with the show’s audience falling by 40% in its second season to 546,000 viewers.