Rosa Foods Inc., maker of the Soylent meal replacement drink, just boosted the nascent office market in downtown’s Arts District, signing a large lease just under $4 a square foot monthly, according to a source familiar with the deal.

Rosa has agreed to take 29,000 square feet at a retail and office complex under construction on Mateo Street, according to project developers ASB Real Estate Investments and Blatteis & Schnur.

Four-year-old Soylent currently leases about 14,000 square feet at the Broadway Civic Center downtown.

The move won’t come until May at the earliest, when the Arts District project, called At Mateo, is scheduled to open. The $80 million development consists of ground-up construction in an industrial style that will offer 50,000 square feet of office space and 125,000 square feet of retail space.

“Signing a cutting-edge food company like Soylent is an auspicious way to kick off the project’s office leasing,” ASB President Robert Bellinger said in a statement.

Asking monthly rents on other Arts District projects range from $3.50 to $4 a square foot, local brokers said, while Warner Music Group Corp. signed a lease in October to occupy the Ford Factory at a monthly rate of about $3.24 a square foot, according to public filings.

Office leasing in the Arts District is at a point of flux as more than 1 million square feet of high-end space are under development in a market that, until recently, was home to industrial companies. Other than Warner Music, few high-profile companies have flocked to the area, although Hyperloop One, a high-speed tube transport startup, began leasing space there in 2015.

“Downtown Los Angeles has been the perfect home for our growing business,” Rob Rhinehart, founder of Soylent and Rosa Foods, said in a statement. “The Arts District is a hub of diversity, creativity and innovation.”

CBRE’s Daniel Rainer and Blake Mirkin represented At Mateo in the deal, while Tucker Hughes of Hughes Marino represented Soylent.

Cushman & Wakefield’s Andrew Tashjian has since taken the listing for the remaining space.

Real estate reporter Daina Beth Solomon can be reached at dsolomon@labusinessjournal.com. Follow her on Twitter @dainabethcita for the latest in L.A. real estate news.