NEW YORK CITY—What began as a 100-million-share stock sale earlier this week has ended up totaling 138 million shares when the underwriters on American Realty Capital Properties‘ public offering had their say. The net lease REIT said Thursday evening that underwriters had fully exercised their overallotment option, buying an additional 18 million shares at $12 apiece, culminating one of the largest REIT equity offerings on record.

ARCP is expecting total net proceeds of $1.59 billion from the upsized stock sale, which law firm Proskauer Rose said was the third largest stock offering in REIT history at 120 million shares before the underwriters exercised their option. Despite its coinciding with the acquisition announced last week of more than 500 Red Lobster properties in a $1.5-billion sale-leaseback, the stock sale will not be used to fund that deal, but instead will go for paying down debt and other general corporate purposes.

As reported earlier this week, the Red Lobster SLB will be funded via recycled capital from the sale of substantially all of ARCP’s multi-tenant shopping center portfolio to Blackstone Real Estate Partners VII for $1.98 billion in cash. The 11.7-million-square-foot portfolio came as part of ARCP’s $11-billion merger with Cole Real Estate Investments, which closed this past February.

Originally, the portfolio was to be spun off into a separate REIT that would have been known as American Realty Capital Centers. “The previously announced spin-off of our multi-tenant portfolio created visibility and optionality for ARCP in connection with its multi-tenant assets,” Nicholas Schorsch, ARCP’s executive chairman and CEO, said earlier this week. “Thus, we were able to explore various avenues to create stockholder value during the time we prepared for the spin-off. We now believe the sale of the multi-tenant portfolio will deliver the best value creation option to our shareholders and serve to enhance the clarity of our single-tenant, net lease investment strategy, further simplifying and rationalizing our business plan.”

BofA Merrill Lynch, Citigroup, Barclays, J.P. Morgan, Capital One Securities, Credit Suisse, Deutsche Bank Securities and Wells Fargo Securities acted as joint bookrunners for the offering. Proskauer advised ARCP on the stock offering.

Separately, ARCP announced earlier this week that in view of the Red Lobster deal meeting its full-year acquisitions target of $3 billion, it would raise the bar to $4.5 billion in buys for calendar 2014.