'occasionally maintained' is correct and usable in written English.
You can use it when you are referring to something that happens infrequently or not on a regular basis. For example: The garden is occasionally maintained by the local community group.
However, anecdotal evidence shows regulated firms occasionally maintaining cost-inefficiency under incentive regulation even under slumping profitability.
Thereafter, stand upright, but feel free to bend occasionally to maintain your connection.
Wild male and female flies were added occasionally to maintain variability within the strain.
Greeting cards were used occasionally to maintain communication with participants, however, interviewees were negative about the impact of these on retention and questionnaire response, with the exception of the use of birthday cards in paediatric trials and Christmas cards sent to sites from coordinating centres.
Change your password occasionally to maintain the security of your account.
Craig Kieswetter then fell early, extending a poor run that has now brought him only 87 runs from his last six international t20 innings, but Hales's ability to play big and occasionally unorthodox shots maintained momentum.
Occasionally, this was maintained by use of an 8- or 10-Fr sheath, particularly when dealing with stone extractions.
To our knowledge, over the millions of years of evolution, mutations have occurred occasionally and are maintained or lost by inheritance and natural selection.
Occasionally, as MC5 once maintained, they need to kick out the [folk] jams and some of their bucolic, Hobbit-like songs are a bit creepy, as on the ripe "The Hexamshire Lass" where they claim "Her breasts are deep and cool/ they'll warm when I get near her".
In this hypothesis low frequencies of homologous recombination are maintained and occasionally acquire novel genes that result in virulence by horizontal genetic transfer.
