EastEnders actors Nigel Harman and Letitia Dean, who play Dennis Rickman and Sharon Watts, are leaving the soap.
Letitia Dean and Nigel Harman will concentrate on other roles
Harman, 32, is quitting by "mutual, amicable decision" with producers, an EastEnders spokesman said.
He will make his final appearance on the BBC soap at the end of the year, when Dean - a founding cast member - will take an extended break.
"We do not know when she will come back, but she will return," the spokesman said.
Harman's character Dennis is due to marry his adopted sister Sharon on the BBC One soap later this month.
Their wedding will coincide with the discovery of the body of murdered character Den Watts - Dennis' father and Sharon's adoptive father - who was played by Leslie Grantham.
The EastEnders spokesman would not reveal the pair's closing storyline, as the two actors leave to concentrate on other roles.
Dean, 37, was in EastEnders for a decade from 1985 and has already taken a number of breaks from the show.
EastEnders regularly attracted up to 14 million viewers until 2004 but it has recently struggled to match the ratings of its ITV1 rival Coronation Street.
Harman and Dean's departure at the end of the year will coincide with that of Jessie Wallace, who plays Kat Moon.
It comes as previous EastEnders cast members Mike Reid, Barbara Windsor and Ross Kemp are due to return to the soap.