The Lawyer understands that, when Permira opens an office in Tokyo in the autumn, it will be beauty parading Freshfields Bruckhaus Deringer and Linklaters in addition to Clifford Chance and Simpson Thacher.
Permira's move underlines a new shakiness in its connection with Clifford Chance. The Lawyer can reveal that, despite Clifford Chance partner Matthew Layton's warm association with the private equity house, the institutional relationship was soured last year after the global firm closed its West Coast offices in the middle of a key transaction for Permira.
On that deal - an aborted IPO for San Diego-based Memec - Simpson Thacher acted for underwriter Credit Suisse and Goldman Sachs.
On the subsequent $676m (£388.6m) sale of the company to Avnet, Permira snubbed Clifford Chance and turned to Simpson Thacher Los Angeles head Daniel Clivner for the US work.
Permira's decision to consider Simpson Thacher for its new venture in Japan will be a significant test of whether Clifford Chance can hang on to one of its pivotal clients. Simpson Thacher has a strong track record in Japan, where Clivner has represented acquisitive US house Ripplewood Holdings on a series of major transactions.
Permira regularly uses Freshfields as second string adviser on European deals and recently brought in Linklaters on its acquisition of Spanish retailer Cortefiel.
Clivner said: "We'd be delighted to be considered."
Freshfields, Linklaters and Clifford Chance declined to comment. Permira did not return calls for comment.