Google has a PR problem because it is not paying enough corporation tax, Boris Johnson said.
He said large multinational companies need to "show a greater commitment to society" and pay more tax.
The row started when the London mayor made a speech to business leaders in Britain last week, claiming it was "absurd" that the low paid were being forced to pay increasingly high taxes while large corporations paid a tiny fraction of their profits to the Treasury.
He singled out Google, prompting the company's vice president in northern Europe, Matt Britten, to criticise the mayor for not doing enough to support technology companies. He attacked the mayor for "not getting his facts right" by claiming Google paid "zero" tax when it paid £6m on UK sales of £2.5bn.
The timing of Mr Britten's broadside is embarrassing for the mayor who is touring Hyderabad in India to promote links with London. Apart from Bangalore, Hyderabad is the emerging silicon valley of India and Mr Johnson specifically visited the city to promote stronger links between it and London's high-tech industry.
But the mayor decided to stand by his initial criticisms, claiming Google had a PR problem.
He said: "My point is very simple: we all need Google, we all love Google. But here's the thing, it seems to me the point stands.
"You either change your tax arrangements or, as I have repeatedly said, great corporations that live and work and profit from the society that they are in should do a little bit more.
"They have got a PR problem and the way to address that, because people feel a company like Google makes shed-loads of money, is by showing a greater commitment to society."
But Mr Britten said the mayor should look at the "broader contribution" made by Google.