Julia McKenzie in Agatha Christie's "Marple" (ACORN MEDIA GROUP)

For an undisclosed sum, Acorn bought a 64 percent stake in Agatha Christie Ltd. — the co-production partner of ITV Studios, which produces dramas based on Christie’s works for its parent network in the UK.

The Christie family hangs on to its 36 percent stake.

The UK media company Chorion had the majority stake in Christie’s literary estate for nearly 14 years. But Chorion has been selling off brands since putting its assets up for sale last year to repay debts, as it went into the UK equivalent of Chapter 11.

(Chorion has also been home to such other beloved British literary brands as the Beatrix Potter literary estate.)

Chorion’s loss is Acorn’s gain. Since 2001, Acorn Media has been releasing on VHS, DVD and digital its TV-movie adaptations featuring famous Christie characters Poirot and Marple. They rank among the company’s best-selling series of all time.

ITV network recently commissioned new episodes of Poirot and Marple that are scheduled to begin production this summer for broadcast in 2013 on ITV and PBS. Feature-film adaptations are also in development, Acorn said.

The Christie acquisition is another step in Acorn’s evolution into content ownership and television production.

In much the same way, Acorn bought the British crunchy-gravel franchise “Foyle’s War” in 2010 from UK production indie Greenlit Rights, which also went into so-called “administration.” That deal marked the first time Acorn had bought ownership rights to one of its British series.

“Foyle’s War” was one of Acorn’s top-selling franchises on DVD for many years; it last aired on PBS in May of ’10.

“Foyle’s War” — set during and after WWII, in Hastings, on the south coast of England — stars Michael Kitchen as methodical Det. Christopher Foyle, a widower who, assisted by his driver Samantha, catches criminals by taking advantage of the confusion created by the war.

Acorn announced last month that Kitchen was returning for three new episodes.

“We believe Acorn will be a great future partner for the Christie family and will continue to nurture and treasure this property,” Chorion said Thursday in the announcement of the Christie estate deal.

In the announcement, Acorn noted Christie has sold more than 2 billion books and is the best-selling novelist of all time — behind only the Bible and Shakespeare.