The decades-old promise of three-dimensional entertainment is quite suddenly coming to fruition in just a matter of weeks.

After the runaway 3-D success of James Cameron’s Avatar, two separate groups announced on Tuesday plans to launch dedicated all 3-D television channels in the U.S. market.

Discovery Communications Inc., Sony Corp. and IMAX Corp. plan to start a 3-D cable-TV channel in 2011 and ESPN said it will launch a sports station in June.

The Discovery-Sony-IMAX joint venture, which doesn’t have a name yet, will air 3-D shows 24 hours a day, seven days a week in the U.S. market, the companies said on Tuesday. Discovery, based in Silver Spring, Md., Sony and Imax will own equal stakes in the channel. Terms weren’t disclosed.

Discovery, operator of the TLC and Animal Planet networks, will distribute the new channel, which will show movies and programs about natural history, space and science. Hollywood studios are planning to release Blu-ray discs in 3-D this year after record box-office sales in 2009, boosted in part by higher ticket prices for 3-D films.

Mississauga, Ont.-based IMAX has been a big leader of the 3-D charge. The company said on Monday it topped US$100-million in gross box office receipts in the fourth quarter, the first time the big-screen film company breached this milestone.

IMAX booked US$54-million alone from Avatar and said its original title Under The Sea 3D, also was a big contributor.

Shares of IMAX have more than doubled over the past year.

Walt Disney Co.’s ESPN announced on Tuesday it will start ESPN 3D in June. The network will show at least 85 live events in its first year, including matches from the soccer World Cup.

The cable network said it will launch on June 11 with the first 2010 FIFA World Cup match, featuring South Africa versus Mexico.

Other events to be produced in 3-D include the 2011 U.S. college football championship, certain college basketball games and the Summer X Games.

Sony, the maker of Bravia televisions, last month said it would begin using technology from RealD to make 3-D-capable TV sets this year. Suwon, South Korea-based Samsung Electronics Co. announced a similar deal with RealD yesterday.

TV programmers’ move into 3-D comes ahead of this week’s Consumer Electronics Show in Las Vegas.

Avatar, Mr. Cameron’s futuristic 3-D adventure, crossed the US$1-billion mark in global box-office sales last weekend and is poised to be the second-highest-grossing film ever only behind the Hamilton, Ont., native’s own Titanic. Avatar, produced by News Corp.’s Twentieth-Century Fox, also set a U.S. record for a 3-D movie in its opening weekend.