The firm was beaten to the top spot in this sector by Goldman Sachs International Financial Services London.
However, it came ahead of rivals KPMG London and Deloitte London which were ranked fifth and seventh respectively.
Last year, the three firms were ranked fifth (PwC), eighth (KPMG) and sixteenth (Deloitte).
Overall winner of the title of best big company to work for in any sector was Iceland, the frozen food supermarket chain.
According to the Sunday Times, people don’t just like working for the company, 'they love it'. The paper, which is publishing the full 100-firm report this weekend, states ‘The more than 23,000 employees, most of whom work part time, report that they have more fun with colleagues than at any other firm and that they are the least stressed.’
Chief executive Malcolm Walker personally wins an award for best leader of a big company and the company also gains a second award for the most improved company – it jumped five places last year.
The full list of the best companies to work for will appear in the Sunday Times and at thesundaytimes.co.uk/best100companies on Sunday (4 April).
The paper revealed its list of the top 100 small companies to work for last weekend (26 February).