Welsh rival to Catherine Cookson's crown sells BBC the rights to televise eight novels

Her books sell in the thousands but until now only devotees of the romantic saga have known the name of Catrin Collier. All that is to change after the BBC snapped up the television rights to her eight novels and predicted that Collier would become as successful as Catherine Cookson.

The first novel in the series, Hearts of Gold, a story of true romance conquering adversity, is to be filmed as a two-part drama by BBC Wales this summer. If successful, the whole series will become a £20m blockbuster for BBC1 over four years.

The BBC believes the dramas could rival ITV's long-running and popular adaptations of Catherine Cookson novels during the 1990s.

But instead of Cookson's combination of tragedy, poverty and romance in the North-east, the Collier books feature two families – one Welsh, one Italian – in the Wales of the 1930s depression through to the post-war years of the 1950s.

The project is being developed by Matthew Robinson, BBC Wales head of drama, who used to be the executive in charge of EastEnders.

He said: "There are eight books in all, and the stories in Catrin's novels have the potential to develop into a four-year project, which could be worth around £20m to BBC Wales and could run to 2007."

Collier was in her forties before her first novel was published. She became a full-time writer only four years ago when she was 50. She said the deal was incredible.

Although it will not make her a fortune immediately, she admitted: "With repeats and so on, it could revolutionise my entire life ... I considered I was incredibly privileged to get a book published and then the next goal was to make a living out of it. I didn't even dare dream about this. It would have been insane."

Hearts of Gold tells the story of a Welsh nurse, Bethan Powell, from a troubled family background, whose relationship with the wealthy Dr Andrew John seems doomed to failure.

The first two-part drama is currently being cast, ready to start nine weeks of filming next month. It is expected to be screened next year. Scripts for the second book have been commissioned.

The project could provide a huge fillip to film making in Wales. Mr Robinson said: "Hearts of Gold is a really Welsh project: it has a Welsh setting, a Welsh theme, a Welsh writer and Welsh casting."

Collier was born in Pontypridd, which is the setting of the series. After spending time in Europe and America as a management consultant, she returned to Wales, where she now lives on the Gower peninsula.