Eversheds and Foley & Lardner have broken off merger talks that could have created a £815m ($1.25bn) revenue transatlantic firm.

Last month Legal Week revealed that the pair, which have long had a best friends relationship, were in talks.

But those talks have now ended and a merger between the pair is off.

The American Lawyer reports, Foley & Lardner chairman and chief executive Jay Rothman issued a memo to staff at the US firm on Monday saying any merger deal with Eversheds was now off the table.

He said: "We have had a mutually beneficial, non-exclusive referral relationship with Eversheds for a number of years. Although from time-to-time during that period there have been preliminary conversations around exploring a more formal affiliation between the two organisations, no decision was ever made by Foley to pursue such an affiliation."

He added: "We have advised Eversheds that we are not interested in engaging in further discussions on that topic."

A spokesperson for Eversheds said the firm would "not be commenting on every informal conversation that begins and ends".

He added that a "number of options remained open" to the firm and its "global strategy remained unchanged".

Eversheds has made a US merger a key plank in its strategy in recent years. The firm has had ambitions in the US since at least 2011, as part of its plans to become a global player.

At its 2014 conference in Rome, the firm's partners voted to back the firm's plans to pursue a US merger.

Eversheds management are thought to have been speaking to a number of US firms over the past year, after having drawn up a shortlist of likely candidates.

Milwaukee, Wisconsin headquartered Foley has 17 offices across the US and nearly 900 lawyers. It has international offices in Brussels, Shanghai and Tokyo.

According to The American Lawyer, Foley is the 47th largest law firm in the US, with revenue of $665m (£434.63m). It has 849 lawyers and 153 equity partners.

By contrast Eversheds is the 13th largest law firm in the UK, with a 2014-15 revenue of £380.7m and an average profit per equity partner (PEP) of £741,000. The firm has 1,211 lawyers, and 332 partners, of which 118 are equity partners.

A combination between the two would have created a firm with revenue of around £815m ($1.25bn), placing it on the fringe of the global top 20.

Foley & Lardner did not respond to requests for comment.