* 'Lorax' falls to second

* Total weekend sales 6 percent below last year

By Lisa Richwine

LOS ANGELES, March 18 (Reuters) - A comic spin on 1980s television hit "21 Jump Street" nabbed the No. 1 slot on North American movie box office charts over the weekend, beating forecasts and knocking two-time winner "The Lorax" to second place.

"Jump Street" locked up an estimated $35.0 million in U.S. and Canadian ticket sales from Friday through Sunday, according to studio estimates compiled by Reuters. The performance prompted distributor Sony to order a sequel.

The movie stars Jonah Hill and Channing Tatum as bumbling young cops who go undercover to bust a high-school drug ring. The TV show was a more serious teen drama that launched the career of Johnny Depp, who appeared in a cameo in the new film.

Critics liked the makeover, with 87 percent giving the movie a thumbs-up in reviews collected on the Rotten Tomatoes website. Audiences graded the film a "B" on average in polling by survey firm CinemaScore.

Going into the weekend, Sony had projected sales around $25 million in U.S. and Canadian theaters for "Jump Street." Sony's Columbia Pictures and MGM produced the film for about $42 million.

Advance screenings and an Internet marketing campaign helped build buzz ahead of the movie's debut, said Rory Bruer, president of worldwide distribution for Sony Pictures.

"I think we were very successful in getting an opening like this with tremendous word-of-mouth," said Bruer, who confirmed the studio planned a sequel.

Males made up 53 percent of the movie's audience, with half of filmgoers under the age of 25 and half older than 25.

"Jump Street" was the only new nationwide release over the weekend, which for the first time this year lagged the same frame in 2011. Ticket sales for all movies slumped 6 percent from a year ago, according to the box office division of Hollywood.com. Year-to-date receipts are running nearly 16 percent ahead of last year.

HOLDOVERS HANG ON

This weekend, "The Lorax" fell to second place with $22.8 million at North American (U.S. and Canadian) theaters. Sixteen international territories brought in $14.1 million. The family film about a fuzzy, orange creature that speaks for the trees has grossed $172.5 million around the globe since its debut.

In third place, Disney's costly sci-fi epic "John Carter" pulled in $13.5 million domestically, dropping 55 percent from its disappointing start a week earlier. The movie added $40.7 million from overseas theaters during the weekend.

The film about a former military captain who is transported to Mars remains far shy of turning a profit. Total "John Carter" ticket sales now stand at $179.3 million worldwide. The movie cost an estimated $250 million to produce plus tens of millions to market.

In the fourth and fifth spots, comedy "Project X" about a high-school party that spins out of control took in $4.0 million domestically, while "A Thousand Words," starring Eddie Murphy as a literary agent with limited words to speak before he dies, earned $3.8 million.

Also this weekend, Spanish language comedy "Casa De Mi Padre" starring Will Ferrell earned ninth place in limited release. The movie took in $2.2 million at 382 theaters.

The movie division of Sony Corp released "21 Jump Street." Comcast Corp's Universal Pictures distributed "The Lorax." "John Carter" was released by Walt Disney Co. Time Warner Inc's Warner Bros. distributed "Project X" and Viacom Inc's Paramount Pictures distributed "A Thousand Words."

Lions Gate Entertainment released "Casa De Mi Padre."

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