The majority of marketers will not increase their advertising spending as a result of the new agreement between Yahoo and Microsoft.

This is according to a new poll by ClickZ, which found that 63 per cent of those questioned will not be investing more of their budgets into search advertising following the move.

Speaking to the news source, marketer Meg Walker explained that there is uncertainty about how well the services offered by the two companies will be integrated.

"Since I do both SEO [search engine optimisation] and PPC [pay-per-click], I'm disconcerted by the choices for what will control which," she remarked, adding that while Yahoo Site Explorer is ideal for those carrying out SEO, webmaster tools offered by Microsoft as part of its Bing search engine are "rudimentary at best".

However, Microsoft's senior vice president Yusuf Mehdi noted that the two firms will utilise the best of their combined technologies, adding that Yahoo's work in the areas of algorithmic and paid search have been "fantastic".

The deal between Yahoo and Microsoft was announced earlier this week, with the pair signing a ten-year agreement in an effort to reclaim some market share from Google.