An independent advisory firm has given its stamp of approval to the offer by Dole Food Co. Chairman and Chief Executive David Murdock’s to take the company private for $13.50 a share.

Institutional Shareholder Services (ISS) issued a report recommending that Dole shareholders support the merger. ISS, owned by New York investment firm MSCI Inc., is a leading firm that advises investors how to vote on corporate issues.

The Oct. 16 report cited the “meaningful premium” Murdock offered to buy the Westlake Village produce company. The $13.50 offer represented a 32 percent premium over an initial $12 a share offer in June.

The offer values the company at roughly $1.6 billion, including debt. Murdock already controls 40 percent of the stock.

The deal was unanimously approved by the company’s board of directors, but is still subject to approval by a majority of shareholders not affiliated with Murdock. Stockholders are scheduled to meet on Oct. 31 to decide on the offer.

The Los Angeles billionaire took the company private once before in 2003 after paying $33.50 a share in a deal valued at $2.5 billion. He then relisted Dole in a $1.1 billion second initial public offering in 2009.

Dole is now a significantly smaller company after selling off its global packaged goods business and Asia fresh foods business to a Japanese firm for $1.7 billion in April. The business accounted for about a third of revenue and half of profits.

The deal will be financed through a combination of cash and equity. Last year, Murdock sold the Hawaiian island of Lanai for $500 million to Oracle Corp. Chairman Larry Ellison.

On Monday, Dole announced an offering of $275 million in Senior Secured Notes, the net proceeds of which will be used to finance a portion of the merger. The offering will be made available to qualified institutional buyers and come due in 2019.

Shares closed up a penny to $13.74 on the New York Stock Exchange.