Six law firms have made it into The Sunday Times' annual Best Companies to Work For rankings, with Withers and Mills & Reeve the only representatives from the UK's largest 50 firms by revenue.

Private client specialist Withers is a new entrant at number 77 in the rankings, with Mills & Reeve holding steady at number 90.

Lewis Silkin has emerged as the highest rated law firm in 19th place – a significant improvement on the 2011 rankings when the London firm featured at number 43.

Mishcon de Reya, last year's highest placed law firm, is the next best placed firm, featuring at number 23 – a slight increase on its 2011 ranking when it came in at number 28.

Reed Smith and Baker & McKenzie also feature in the rankings, which are compiled from the views of 231,599 employees on areas including leadership; line management; personal growth; pay and benefits; well being; colleagues and corporate social responsibility.

Reed Smith is a new entrant at number 88, while Baker & McKenzie features at number 70, down from 59 in 2011.

Brabners Chaffe Street, which featuring at number 81 last year, does not appear in this year's rankings, which were published in full yesterday (4 March).

Commenting on the rankings, Lewis Silkin managing partner Ian Jeffery said: "The fact that our people feel so positively about the firm reflects the commitment shown by a great many people over the years to our culture and values."

He added: "There is a strong belief within the firm that time spent at work should be enjoyable and that in working with great clients and great colleagues we can make that a reality."

The Sunday Times rankings are split into three – the 100 Best Companies, which cater for companies employing between 250 and 4,999 staff; the 25 Best Big Companies, which cover those with more than 5,000 staff and the 100 Best Small Companies.

UKRD tops the 100 Best Companies rankings, Iceland heads the Big Companies rankings and Shine leads the small company rankings.

Mishcon de Reya managing partner Kevin Gold said: "I am particularly proud that, over a period of such significant growth, we have maintained a culture that makes this such a great place to work."