This work addresses the problem of the "exponential explosion" of the number of states in a finite automata recognizing a set of regular languages specified by the union of regular expressions of the class.*R1.*R2.*, where R1 and R2 are arbitrary regular expressions. A method for reducing the number of states by extending the set to be recognized is proposed. Unimprovable estimates on the number of states of the automata under such modification in the case of an alphabet consisting of at least five symbols are presented. It is shown that the relative gain in the number of states may take arbitrary values. The efficiency of the method suggested is analyzed on regular expressions of Snort.