Marin Software, which offers software to advertisers and agencies to manage ad campaigns across search engines, has raised $13 million in a third round of funding.

The software, delivered online (SaaS), manages these paid search ad campaigns across sites such as Google, Yahoo and MSN. VentureWire reported the news this morning.

DAG Ventures led the round, with includes participation from new investor Focus Ventures and existing investors Benchmark Capital and Amicus Capital. Chris Lien, chief executive of Marin Software, would not comment on the valuation but said it was an up round, meaning that the valuation of the company has increased — which is notable at a time like this, when investors are pushing for lower valuations.

The company targets customers spending a minimum of $1 million a year, the company said. It has now raised at least $25.25 million.