Google is still by far America's most popular search engine, figures show.

According to web tracking firm Hitwise, Google powered about 64 per cent of all US internet searches in the four weeks ending March 31.

Google accounted for nearly 59 per cent of all searches in the same period a year earlier.

Yahoo came second with a 22 per cent share, followed by MSN with 9 per cent and Ask with 3 per cent.

The remaining 48 search engines in the Hitwise Search Engine Analysis Tool made up the remaining 2 per cent.

"Google's growth shows no signs of slowing," said Bill Tancer, general manager of global research at Hitwise.

"Despite capturing the majority of searches in the US, and in light of competitor's improvements, Google's market share of executed searches continues to grow, exceeding 10 per cent growth year-over-year."