Time Warner and Comcast Corp. are trying to come up with cable’s answer to Hulu.

The showbiz conglom and the nation’s largest cable operator have joined forces in a bid to make more cable programming available for free viewing online — without raising the ire of cable and satellite operators.

The partners announced Wednesday plans for a national technical trial of the “TV Everywhere” initiative that Time Warner CEO Jeff Bewkes has been tubthumping for the past few months.

The goal is to make more pay and basic cable shows available for online viewing, but with the catch that programming would be available only to viewers who already subscribe to cable, satellite or telco services. Viewers would receive a password from their service provider in order to have on-demand broadband access to cable shows.

The trial announced by Bewkes and Comcast chief Brian Roberts at a news conference Wednesday will involve 5,000 Comcast subscribers. They’ll initially be able to watch selected TNT and TBS shows, including “The Closer,” “Saving Grace,” “Tyler Perry’s Meet the Browns” and “My Boys” online via Comcast’s Comcast.net and Fancast.net platforms, as well as through the TNT and TBS websites.

The partners said the trial also would involve feature films and programming from 10-15 cablers, including non-TW outlets, but they would not offer specifics. It’s also expected that selected HBO programs will be involved in the trial. Time Warner Cable already is in the midst of a similar trial in Milwaukee involving HBO programs.

Reaction to the formal unveiling of TV Everywhere from other major players was muted on Wednesday. Fox and Disney-ABC Television Group declined comment; a rep for Hulu did not respond to a request for comment.

CBS, which beefed up the full-length series content offered on its TV.com website in recent months, issued a noncommittal statement asserting “initiatives like TV Everywhere and (Comcast’s) OnDemand Online are the very reason why we believe it’s imperative to control our own programming online.”

While the broadcast nets have been quick to make an array of programs available online, cable programmers have been more cautious out of concern of a backlash from cable operators, who fear that they’ll lose subscribers if top shows are made available for free online. The password-protected access plan is seen as a biz-friendly compromise that protects the revenue base of cable operators and the channels that rely on them for subscription fees.

Disney is about to join News Corp. and NBC U as an equity partner in Hulu, the website whose rapid growth during the past two years has helped drive more online viewing of full-length episodes of primetime skeins. Disney has been aggressive in making some shows available for broadband viewing via its various network websites, particularly ABC.com, but the Mouse has held back on some of its top cable properties, including “Hannah Montana.”

The trial that begins next month is primarily an effort to test the security aspects of the password-protected system. Skeptics of the TV Everywhere plan have said that it would likely be vulnerable to hackers and file-sharing networks, and might be thwarted by authorized users giving away their passwords.

Another key focus of the trial for TW and Comcast is to fine-tune a system with Nielsen so that online viewing can be included in a show’s overall “C3” rating, which has become the benchmark for advertising sales.

The C3 rating, which measures viewing of commercial breaks within three days of a program’s initial telecast, already incorporates viewing done via DVR, but broadcast and cable nets have been eager to add in the online numbers, as more viewers are turning to Hulu and online sources to catch up with shows. The ability to cume online viewing into a program’s overall C3 rating would go a long way toward assuaging the concerns of broadcast net execs who are worried that having so many shows available for free online is cutting into ratings for traditional telecasts that still bring in the biggest advertising paydays, by far, compared with online ad revenues.

The initial TV Everywhere trial will involve only Comcast and Time Warner-owned platforms. Matt Strauss, Comcast’s senior veep of new media, emphasized that the goal was to test out the security system the cable giant has been working on for months in carefully controlled environments.

But the partners also stressed that the TV Everywhere plan is designed to be open and nonexclusive over the long term, meaning cable programmers would still be free to cut online deals with other distribs beyond Comcast.

Comcast intends to begin the trial by next month, and it hopes to roll out TV Everywhere on a national basis by year’s end.