Online ad firm ValueClick is to buy US company MeziMedia, which operates shopping comparison sites, for a price that may eventually reach $352m (£172m).

The eventual value of the deal will depend on whether performance targets are met by 2009, with $100m (£49m) to be paid upfront in cash.

Founded in 2001, MeziMedia employs around 160 staff worldwide, is headquartered in LA and has offices in China and Japan. The company generated revenues of around $40m (£20m) last year.

Its portfolio includes and, as well as sites in Spain, Germany, France and the UK.

The deal will give ValueClick a boost in the US, as well as a presence in China, where MeziMedia operates shopping comparison and coupon sites.

ValueClick has been talked up as an acquisition target itself, especially after the recent consolidation frenzy that has seen DoubleClick, 24/7 RealMedia and others snapped up.