Weil, Gotshal & Manges is confronting a wave of partner defections as two groups of high-profile attorneys explore moves to rival firms.

One group, including Christopher Machera, co-head of Weil's private-equity group and management committee member, is set to join Paul Weiss. Machera ranks among the firm's top revenue producers.

A second group, featuring Brian Parness, a private-equity partner who has represented clients like Brookfield and TPG, is in talks with Simpson Thacher & Bartlett. Those familiar with the situation caution that these plans remain unconfirmed.

The departures mark the latest disruption at the storied Wall Street firm, which has long advised major private-equity shops and guided companies through bankruptcies. If the moves proceed, they would represent a significant shift of talent and client relationships to competing elite practices.