Long-serving Coronation Street star Julie Hesmondhalgh is leaving the soap after 15 years as TV favourite Hayley Cropper.

The Accrington-born actress, 42, admitted she has had "the most wonderful time" playing the Street's first transsexual on the ITV1 show, but wanted to pursue new projects after starring in the play, Black Roses: The Killing Of Sophie Lancaster at the Royal Exchange Theatre in Manchester last year.

"I've had the most wonderful and happy time in the life-changing 15-16 years I've been in Corrie, and I owe so much to the show and the special team that make it happen," she said.

"The decision to hang up Hayley's red anorak was a tough one, but doing the play at the Royal Exchange last year made me realise that there's life in the old dog yet (!) and that there are other things I want to try."

She added: "Whatever happens next I'll always be proudest of lovely Mrs Cropper and in particular what we achieved in changing attitudes to transgender and in portraying possibly the most loving, faithful and steadfast couple in soap history! I'll always be the show's biggest fan."

Hesmondhalgh, who joined the soap in 1998, will fulfil the rest of her contract until the end of 2013.

TV bosses are now working on storylines to ensure a "dramatic exit" for such a beloved character.

Executive producer Kieran Roberts said: "Who doesn't love Hayley Cropper? The character's warmth and decency, spiced with a great sense of fun and adventure, have put her at the heart of Coronation Street.

"The enduring popularity of and affection for Hayley - and of course her wonderful partnership with Roy - has so much to do with the brilliant way Julie Hesmondhalgh has brought the character to life on screen for the past 15 years.

"We'll be sorry to say farewell to Hayley - and to Julie - but we're planning a screen exit worthy of one of Coronation Street's best-loved characters."

Hesmondhalgh, who is married to actor and writer Ian Kershaw in real life, has taken hiatuses from the show. She took time off in 2001 to give birth to her daughter Martha Mo, and had a year's break in 2007 to spend more time with her family.

Her alter-ego Hayley and cafe owner Roy Cropper (played by David Neilson) are now one of the programme's best loved couples, having won over the hearts of the nation with their romance.

The screen couple have been at the heart of major storylines including being caught in Tracy Barlow's web of deceit when she claimed Roy fathered her child in an attempt to steal their savings. Hayley has also had to relive her background with the arrival of her mother-in-law Sylvia (Stephanie Cole).