He was also charged previously with four counts of making indecent images of a child in the first half of 2012.
The additional counts revealed on Sunday include one offence of indecent assault "relating to a girl aged seven or eight in 1968 or 1969", the CPS said.
The artist and singer is also accused of indecently assaulting a girl aged 14 in 1975 and indecently assaulting a girl aged 19 in 1984.
The later offence relates to the same complainant as six of the charges laid in August.
The additional counts were included in the original police file sent to prosecutors in August.
But it was only after a "review process" that the CPS decided the allegations should be formally added to the indictment against Harris.
Prosectors say because evidence relating to the further counts has already been served on the court and the defence, Harris won't appear again at a Magistrates Court.
Rather, the Australian will front Southwark Crown Court on January 14 as previously scheduled for a plea and case management hearing.
Harris has not commented on the allegations since he was first named in the press in April.
He appeared in Westminster Magistrates' Court in September looking frail and confused for his only court appearance to date.
The 83-year-old, who was accompanied by his wife Alwen and daughter Bindi, spoke only briefly to confirm his personal details.
His lawyer indicated the entertainer would plead not guilty.
For the offences committed after 1985 Harris could face up to 10 years' jail.
Harris on Sunday was asked by UK tabloid the Daily Mirror if he wished to comment on the new charges.
"I don't think so, thank you," he said over the intercom at his Berkshire home the paper reported.
Harris was first questioned by officers from Operation Yewtree back in November 2012. He was arrested in March and rearrested in early August before being charged three weeks later.
The Australian is on conditional bail under which he is banned from having contact with anyone under 18 unless he's accompanied by someone over the age of 21.
His trial is scheduled to begin in late April.
During 2013 one-time royal favourite Harris has been dropped as the face of British Paints, the host of hit TV show Animal Clinic and as the narrator on Olive the Ostrich.
His paintings have been removed from cruise liners including the Queen Mary 2 and no-one, including Buckingham Palace, seems to know what's happened to his 2005 portrait of Her Majesty.
- AAP
