The exact figure specified in the financial disclosure is said to be between $100,000 and $250,000.
Trump confidant and adviser Rudy Giuliani described the transaction by saying money was "funneled through" Cohen's law firm.
Mr. Ehrat, who has been Novartis' group general counsel since 2011, made the decision to retire "in the context of discussions" surrounding the payment to President Trump's personal lawyer.
The Mar-a-Lago resort, where the president frequently escapes for winter weekends, collected more than $25 million last year, down from $37 million from last year's report.
U.S. president Donald Trump has valued his golf course in Doonbeg, Co Clare at between $25 million and $50 million (€21.18 million-€42.36 million), according to a financial disclosures form published on Wednesday.
The disclosure, signed by Trump and released by the U.S. Office of Government Ethics, did not describe the objective or the recipient of the original 2016 payment to a "third party" made by Cohen, for which he was reimbursed by Trump.
Chlorine gas likely used in Feb Saraqeb attack - OPCW
The team exhumed bodies and gathered more than 100 environmental samples now being analysed in different OPCW-designated labs. OPCW Director-General Ahmet Uzumcu harshly criticized the chemical attack .
Trump had previously disputed whether he was aware of the payment by Cohen and whether he reimbursed his attorney. The disclosure was not included in Trump's 2017 filing.
The White House confirmed that Trump and Vice President Mike Pence filed their financial disclosures Tuesday, along with the reports of some 25,000 senior executive branch officials, but declined to comment further. It says Trump "fully reimbursed Mr. Cohen in 2017".
"Mr. Cohen, an attorney, received a monthly retainer, not from the campaign and having nothing to do with the campaign, from which he entered into, through reimbursement, a private contract between two parties, known as a non-disclosure agreement, or NDA", Trump wrote on Twitter, reversing an earlier statement that he was unaware of the payment.
President Trump listens during a meeting with Uzbek President Shavkat Mirziyoyev in the Oval Office Wednesday.
Trump's previous report, covering January 2016 through the first few months of 2017, showed he had at least $1.4 billion in assets and at least $594 million in income.