J2 Global Communications Inc. on Thursday said that it acquired the unified messaging and communications business of mBox Pty Ltd., which is based in Australia.

The acquisition, whose terms were not disclosed, will expand j2 Global’s customer base in Australia, New Zealand and Singapore and increase its network of local telephone numbers in those locations, according to the Los Angeles company, which provides outsourced messaging and communication services.

J2 Global’s network now covers more than 3,500 cities in 48 countries.

Shares were up 21 cents, or less than 1 percent, to $23.56 in midday trading on the Nasdaq.