Kelsey Grammer's ruthless Chicago mayor has met his match: Starz, which has opted not to move forward with its political drama Boss after two seasons.

"After much deliberation, we have made the difficult decision to not proceed with [a third season of] Boss," Starz said in a statement Tuesday. "We remain proud of this award-winning show, its exceptional cast and writers, and are grateful to Kelsey Grammer, [creator] Farhad Safinia and our partners at Lionsgate TV."

Starz president Chris Albrecht picked up Boss straight to series, bypassing the traditional pilot stage. The latter is part of Albrecht's larger brand-building strategy for the HBO and Showtime rival, which also includes bold bets and a focus on cinematic dramas over half-hour comedies.

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The series, which earned a Golden Globe nomination for best drama and an acting win for Grammer, drew 659,000 total viewers to its original October 2011 premiere en route to 1.72 million overall over its first weekend, falling shy of recent scripted launches. Season two returned down from its freshman run with a mere 317,000 viewers, ending in October with a season high of 440,000 viewers. The Lionsgate TV drama's sophomore season averaged 937,000 viewers when factoring in multiple premiere weekend airings, down from its first-year average of 1.1 million. Worth noting, Magic City -- which Starz produced in-house -- outperformed seasons one and two of Boss, averaging 1.25 million in its freshman run.

As is quickly becoming commonplace at Starz, the network ordered a second season of the drama nearly a month ahead of its series premiere. The cabler mounted a pricey campaign for awards-season attention for the series, which starred Grammer as a fierce political player battling an incurable degenerative disease and co-starred Kathleen Robertson, Jeff Hephner and Connie Nielsen. Ultimately, the Safinia-created show -- which counted Gus Van Sant and Grammer among its executive producers -- failed to receive recognition outside of the Golden Globes.

Dee Johnson boarded the Lionsgate TV drama as showrunner for season two, which featured the additions of Glee's Jonathan Groff and Sanaa Lathan. Had Boss continued with a third season, Johnson -- who joined ABC's freshman drama Nashville, also from Lionsgate, as showrunner earlier this year -- was scheduled to return to the series, which was in first position.

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Under Starz president Albrecht, formerly of HBO, the premium cable network has been focused on more broadly appealing, commercial dramas, which he has dubbed "premium TV-flavored popcorn." In the past, he has talked about leaving "quieter dramas" -- a la Mad Men -- to the other networks, with his focus on such global hits as Spartacus, which will end its run next year.

Starz is scheduled to launch at least four scripted efforts in 2013, including the final season of Spartacus, season two of Jeffrey Dean Morgan starrer Magic City, period drama Da Vinci's Demons and limited series The White Queen with Janet McTeer. Michael Bay's Treasure Island prequel Black Sails and big swing Marco Polo are in the works.

Grammer -- who has been active as a producer this development season, selling projects to MTV and NBC -- already has lined up his next gig, joining Kyra Sedgwick in the ensemble cast of feature Reach Me.

Update: Sources confirm to THR that Starz has had talks to wrap the series with a two-hour movie. The second season finale tied up the season-long mystery with Grammer's Tom Kane still in full control of Chicago, and with his illness still under wraps.

Email: Lesley.Goldberg@thr.com; Twitter: @Snoodit