King & Wood Mallesons has held talks with Morgan, Lewis & Bockius about a global tie-up, a source briefed on the matter told London-based Legal Week.

The discussions took place within the last few months and involved the top leadership at both firms, the source said. One option on the table was creating a combined entity using a Swiss verein structure, although the recent resignation of King & Wood Mallesons funds partner Michael Halford in London has caused talks to break down and it remains unclear whether they are continuing in any capacity.

King & Wood Mallesons has long sought a deal with a major U.S. firm to complete its global footprint, though given the difficulties in finding a suitable partner it has previously changed tactics to finding an alliance partner instead. King & Wood Mallesons saw gross revenue remain mostly flat over its last fiscal year at $1.02 billion, according to The American Lawyer’s most recent Global 100 rankings, while Morgan Lewis saw gross revenue rise 40 percent, to $1.844 billion, in the year after its agreement to absorb the bulk of now-defunct Bingham McCutchen.

Representatives for Morgan Lewis and King & Wood Mallesons declined to comment.

News of the reported talks, first published by U.K. legal publication Legal Business, comes as King & Wood Mallesons’ new European management team flew to Asia to speak to the firm’s Chinese leadership about finding a way forward for its struggling European arm, which is under pressure following a series of high-profile partner exits. Europe, U.K. and Middle East managing partner Tim Bednall and senior partner Michael Cziesla—who were voted into their new roles in October—have travelled to China to discuss options for the European partnership, which could include the firm’s Chinese partnership providing some form of financial assistance to its legacy SJ Berwin business.

Earlier this year, King & Wood Mallesons announced plans to slash by 15 percent the partnership of its European, U.K. and Middle East arm following an internal review of the business, which it acquired in 2013 via its integration with London-based SJ Berwin. (King & Wood Mallesons was formed two years prior through the combination of leading firms in Australia and China.) This summer, King & Wood Mallesons partners in Europe and the Middle East agreed to commit $18.4 million via a capital call to bolster the business.

That recapitalization plan was halted a week ago when Halford and three other top London partners, including former SJ Berwin managing partner Rob Day, resigned from the partnership. Day and King & Wood Mallesons corporate finance partner Andrew Wingfield are reportedly poised to join Proskauer Rose, a firm that broke off merger talks with SJ Berwin six years ago this month. An assessment of the financial impact of the recent spate of resignations at King & Wood Mallesons should be completed within three weeks.

Halford was one of four of the highest-billing London partners to resign from King & Wood Mallesons. The others are Day, Wingfield and private equity partner Jonathan Pittal. The King & Wood Mallesons quartet, responsible for roughly $11.3 million in annual billings, are being followed out the door by other top partners.

On Friday, Squire Patton Boggs snagged Neil Upton, co-head of the firm’s global energy group and a leader of its energy team in London. A five-lawyer energy team also announced plans last week to leave King & Wood Mallesons’ Frankfurt office for Anglo-German legal giant Taylor Wessing. Among those making that move are German banking and finance head Sabine Schomaker.

CMS Cameron McKenna, another British firm in the midst of pulling off its own three-way merger, is advising King & Wood Mallesons. Rita Lowe, head of banking and finance at CMS, is a frequent adviser to financial institutions dealing with distressed partnerships. King & Wood Mallesons operates separate partnerships under the Swiss verein structure to account for its Australia, China and European arms.

King & Wood Mallesons’ hybrid history and financial issues have led some legal market observers to put the firm on their watch lists. A former partner at the firm, asked about the possibility of a rescue of its European arm from China, said its new European management is “trying to play on the reputational damage the Chinese arm would face if Europe goes under.”

But while the Chinese leadership could be reluctant to bail out Europe, King & Wood Mallesons’ Australia arm could be open to such a plan, said an ex-partner at the firm.

“They may well say, ‘That’s not our problem, we’re making money here,’” said the former partner. “I think it’s something the Australian partnership would contemplate though, and I think it would have pretty dire ramifications on the relationship between Australia and China if China refused to help.”

But another former partner with the firm’s European arm believes that China will come through with some form of financial assistance, noting that, “it’s worth more to the Chinese parts of the business to keep Europe going.”

Morgan Lewis is no stranger to circling firms in financial straits. Besides its deal with Bingham in late 2014, Morgan Lewis has hired large groups of lawyers from defunct firms like California’s Brobeck, Phleger & Harrison; Dewey & LeBoeuf; Howrey; IP boutique Pennie & Edmonds; and Thelen. Morgan Lewis also expanded in Asia last year by combining with Singapore’s Stamford Law Corp.

In May, Morgan Lewis’ chief marketing officer Despina Kartson, a high-profile administrative hire in 2013, left the firm to become global director of business development and communications at Jones Day. Kartson replaced Cherie Olland, who retired from Jones Day in July. In March, Morgan Lewis recruited Dechert’s Colleen Nihill to serve as its new chief administrative officer.