Olswang has kept on just 14 of the 24 newly-qualified (NQ) lawyers in the firm's September intake, equating to a retention rate of 58%.

The firm has said that it did offer 19 places to its trainees, but that some departments were oversubscribed.

A Olswang spokeperson said: "We have a commitment to help our trainees pursue the area of law that genuinely interests them. Our experience shows that trainees that take 'whatever is offered' generally do not prosper in the long term, which is not good for them or the business."

Meanwhile, McGrigors has seen a retention rate of 64% for its September intake after offering roles to 23 of 33 job applicants, from a total of 36 trainees.

The firm had originally committed to offering 30 places, but reduced this to 23 after the application process started.

In a statement, the firm said: "We originally offered our trainees 30 NQ roles but we have had to revise our thinking due to continuing fragile market conditions.

"Unfortunately, this means we will be losing folk who we really wanted to keep in the business. We are going to keep the situation under review over the summer and hope very much to be able to offer a few further NQ jobs."

In contrast, US firm Shearman & Sterling has posted a high retention rate of 91.5%, with 11 of 12 of its September qualifiers offered jobs at the firm.

The numbers were first reported on legal blog RollOnFriday.