The British Broadcasting Corp. and Italian state broadcaster RAI have inked a co-production deal for a four-part drama based on Joseph Conrad’s novel “Nostromo.”

The agreement is part of a wider alliance between the two.

BBC TV’s head of serials, Michael Wearing, said he hoped to co-produce two or three more films with RAI over the next three years.

“We have not been wildly successful with European co-producers in the past,” Wearing admitted. “This is a breakthrough.”

The BBC will still co-produce big-budget, period pix with U.S. partners.

But with the BBC now making two or three serials a year, there’s a limit to how many co-productions the U.S. partners can finance.

Boston’s WGBH-TV, a regular BBC co-producer for more than 20 years, is talking to the BBC about investing in “Nostromo.” It is understood that U.S. pay cabler Showtime has offered to provide coin for the production.

The adaptation, comprising four 90-minute segs, is budgeted at about $15 million with the BBC putting up in 65% of the money. RAI’s stake is believed to be $6.75 million.