A two-day hearing organised by the force found that Police Constable Simon Beech, who was based in Stretford police station, had “abused his position for a sexual purpose” and was guilty of gross misconduct.
The former officer had met the women after attending crimes in which the women either reported or were a witness to.
The Independent Office for Police Conduct (IOPC) said he “showed a complete disregard to the high standards expected of officers”.
The IOPC received a mandatory conduct referral from the force in July 2017 and began an independent investigation, which concluded in November 2018. IOPC investigators arrested PC Beech and searched his home in July 2017.
Investigators discovered that just under 300 phone calls and texts were recorded in the space of a month to one of the numbers linked to the women.
Some of the women identified through the phone calls and messages provided statements to IOPC investigators.
“One woman told us she met PC Beech after being a witness to a crime and she had provided a phone number,” said the IOPC.
Investigators found evidence of PC Beech attempting to pursue inappropriate relationships with four other women by messaging them and this was found proven by the panel.
There were also allegations about contacting two of the women after his arrest and telling them not to speak to the IOPC or Greater Manchester Police about the matter. Again, the panel found these proven.
The disciplinary hearing determined that the former officer had breached police standards of professional behaviour for discreditable conduct and authority, respect and courtesy.
IOPC Regional Director Amanda Rowe said: “Abuse of position for sexual purpose is a form of serious corruption and it’s clear that PC Beech showed a complete disregard to the high standards expected of officers by forming inappropriate relationships with women he met while on duty.
“This abuse of trust seriously risked undermining public confidence in the police and we welcome the panel’s decision.
“The outcome today should provide a clear message to any officer who misconduct themselves in such a way, that they will be held to account and can and will face serious consequences for their actions.”