This paper presents an extension of an algebra of high-level Petri nets with operations for suspension and abortion. These operations are sound with respect to the semantics of preemption, and can be applied to the modelling of the semantics of high-level parallel programming languages with preemption-related features. As an illustration, the paper gives an application to the modelling of a multi-tasking system in a parallel programming language, which is provided with a concurrent semantics based on Petri nets and for which implemented tools can be used.