"they liaise" is a correct and usable form of written English.
It can be used when referring to two or more people working together to achieve a common goal. For example: The sales team and the IT department liaise to ensure their project meets the highest standards.
"We have a point of contact with the NGBs [national governing bodies] and they liaise directly with delegations of staff.
But it does recommend that they "liaise closely with statutory agencies" to assure that any charges "are promptly and properly dealt with".
"Their primary modus operandi is that they don't do things themselves, they liaise with others," said Afshon P. Ostovar, a senior analyst at C.N.A. in Alexandria, Va., who is writing a book about the Revolutionary Guards.
They liaise between station management and staff members and also interact with customers.
At community level, they liaise with each other and with the HSAs.
Youth groups have been linked to CHVs with whom they liaise to get information on which mother or child requires their services.
Each of their former national institutions is in receipt of a large, endangered public grant, and as directors they liaised regularly rather than seeing each other as rivals.
Yet although the Tories say they liaised with the Foreign Office, there was something unseemly about his rush to Tbilisi to the seat of a crisis in its heat before an actual minister made it.
Where the protocol did not specify a course of action the nurse informed the GP and the trial clinician by memo and they liaised to decide what action to take.
More than two thirds of the Social Firms surveyed said they liaised with their local mental health services, either to recruit workers or in order to support employees with their difficulties.
The community, sub-county and district level proved to be particularly important structures for the support of outbreak response activities: they liaised with the community including the index family, organised the cooperation with other sectors (education, environment etc)., and facilitated the collaboration between local authorities and the various international players.
