Aon Plc said on Wednesday it had scrapped plans to pursue a merger with rival insurance brokerage Willis Towers Watson Plc, a day after it revealed it was in early stages of considering an all-stock offer for the Irish company.

Aon’s shares rose 6.19 percent in early trading, recouping some of the losses incurred on Tuesday after news of the potential merger surfaced. The company did not give any reason for abandoning the deal.

An Aon-Willis merger would have been the largest deal in the U.S. insurance industry that is consolidating in the face of uncertainty arising from Britain’s impending exit from the European Union and trade tensions between the United States and China.

Shares of Willis Towers hit an all-time high of 8.6 percent on Tuesday after a Bloomberg report said the companies were in preliminary talks. Aon’s shares fell nearly 8 percent.

Following the report, Aon was forced to confirm that it was in early stage talks with Willis Towers due to Irish regulatory requirements, the company said.

“As a result of media speculation, those regulations required Aon to make the disclosure at a very early stage in the consideration of a potential all-share business combination,” the insurer said in a statement.

Shares of Willis Towers were down 5.24 percent at $172.50 in the premarket trading.

A deal would be hard to make sense, considering regulatory issues it would have faced, wrote Wells Fargo analyst Elyse Greenspan in a note reacting to Tuesday’s Bloomberg report.

Greenspan also said “regulatory issues (among others, including accretion, lost business, etc) could have impacted its (Aon’s) decision not to pursue a deal at this time.”