Aspyr is preparing The Sims: Unleashed, the latest Expansion Pack for the cross-platform classic The Sims series of titles.

Already available on PCs, the Expansion Pack is expected to ship before Christmas in the US – it's not clear if this will be the case in the UK.

Alongside five new career paths – pet walker and circus artist, for instance – and a host of new objects, the title allows for larger Neighborhoods and introduces a brand new feature: Sims can keep pets.

To get pets, Sims must visit the pet shop. There they can choose between a variety of creatures, including dogs, cats and lizards.

Additional Neighborhood improvements include larger homes, parks, shops and a farmer's market. Aspyr says: "Sims can visit the local garden store and grow a variety of vegetables in their own garden plots."

The Sims series has become one of the biggest selling titles across all platforms. Mac-games industry insiders describe the series as a "hardy perennial". Both the original title and its Expansion Packs: Livin' Large; House Party; Hot Date; and Vacation all continue to sell well.

The Sims: Unleashed will be distributed in the UK by Softline. Previous Expansion Packs cost £39.99, though final pricing for this product has not yet been confirmed.

System requirements include: Mac OS 8.6 or higher; G3/233MHz or faster; 192MB of RAM; 2MB of VRAM; and 750MB hard-drive space.