Google is introducing a range of measures to improve its policing of digital piracy, promising to respond to requests for the removal of material that infringes copyright from its search service "within 24 hours".

The US technology giant will implement the measures in the coming months as it attempts to react more swiftly in removing pirated content and to better promote legitimate music download sites. Google is responding to mounting pressure from film and music companies for action over copyright infringement.

The anti-piracy measures will be introduced across Google's main online search service, but not its subsidiary YouTube. More than 35 hours of video is uploaded to YouTube every minute and the quantity of illegal content has sparked legal action from rights holders including Viacom and the Premier League. Google said it has already invested heavily in more advanced anti-piracy measures for YouTube.

Kent Walker, general counsel for Google, said in a blogpost today that the company will "act on reliable copyright takedown requests within 24 hours".

"As the web has grown, we have seen a growing number of issues relating to infringing content," he added.

"We respond expeditiously to requests to remove such content from our services, and have been improving our procedures over time. But as the web grows, and the number of requests grows with it, we are working to develop new ways to better address the underlying problem."

Under the US Digital Millennium Copyright Act Google is required to take down pirated content within a reasonable timeframe once notified.

Walker added that Google will start to censor its Autocomplete search function – which predicts what a web user might be about to input into the search box as they type – to "prevent terms that are closely associated with piracy" from appearing.

For example, if a large number of users have been clicking through to illegal music websites after typing "Lady Gaga" into the search box, then the Autocomplete function would suggest them to other searchers.

However, Google said that it would not be altering the actual search results that are delivered to users, meaning that illegal websites will still appear.

In a bid to promote legal sources of film and music content, Walker said Google would "experiment" with having preview content, such as samples of music tracks, when the search results are returned. "We will be looking at ways to make this content easier to index and find," he added.

Google also said that it would improve the anti-piracy procedures relating to its advertising program AdSense "working with rights holders to identify, and, when appropriate, expel violators".

In a conference call with journalists today, Simon Morrison, copyright policy and communications manager for Europe, Middle East and Africa, made it clear that the measures did not involve video-sharing website YouTube.

Morrison pointed out that YouTube is a "special case" as Google has already spent $30m and "tens of thousands of man hours" building a system for the video sharing website called Content ID, which tags copyright content and allows illegal material to be removed "within a few hours". "We have highly developed practices there," he said.

Geoff Taylor, the chief executive of music industry body the BPI, welcomed the measures but said that Google needed to go further to eliminate digital piracy.

"It is encouraging that Google is beginning to respond to our calls to act more responsibly with regard to illegal content," said Taylor. "However this package of measures, while welcome, still ignores the heart of the problem. Google search overwhelmingly directs consumers looking for music and other digital entertainment to illegal sites."

Taylor called on Google to work with the BPI to find a "technical solution that points music fans to sites that reward artists and everyone involved in creating music".

Communications minister Ed Vaizey said: "I welcome these fresh measures to tackle on-line copyright infringement. They recognise the importance of consumers finding legitimate content. Infringement of copyright is not just a problem for creative industries, it harms the development of new and innovative ways for people to access content legitimately."