Whole Foods' Walter Robb with Instacart's Apoorva Mehta.

Whole Foods Market Inc. and Instacart LLC are expanding their partnership to provide delivery of online or mobile grocery orders in as little as an hour for shoppers in 15 cities.

The companies also plan to pilot an in-store pickup option at Austin, Texas, and Boston stores in the next month, with expansion to the other cities later on. Whole Foods said it will be the first national Instacart partner to offer the in-store pickup service.

AUSTIN, Texas — Whole Foods Market Inc. and Instacart LLC are expanding their partnership to provide delivery of online or mobile grocery orders in as little as an hour, as well as an in-store pickup option, for shoppers in 15 cities.

Whole Foods Market Inc. and Instacart LLC are expanding their partnership to provide delivery of online or mobile grocery orders in as little as an hour, as well as an in-store pickup option, for shoppers in 15 cities.

Whole Foods co-CEO Walter Robb with Apoorva Mehta, founder and CEO of Instacart.

Instacart already delivers groceries from Whole Foods stores in the cities it serves. Those cities are Atlanta; Boston; Austin, Texas; Boulder, Colo., Chicago; Denver; Houston; Los Angeles; New York; Philadelphia; Portland, Ore.; San Francisco; San Jose, Calif.; Seattle; and Washington, D.C.

The partners will pilot a program at selected Whole Foods stores here and in Boston within the next month offering in-store pickup of items ordered via Instacart. The pilot is a prelude to an expansion of the program to all 15 cities where Instacart operates.

"Instacart makes it extremely easy for our customers to buy Whole Foods Market products from 15 cities and have them quickly delivered, whether buying fresh ingredients for dinner tonight or sending healthy foods to loved ones in another city,” says Walter Robb, co-chief executive officer of Whole Foods. “We are thrilled to add this additional convenience for our customers.”

Instacart, launched two years ago in San Francisco, uses software to link customers to grocery stores, then deploys independent shoppers to purchase items and deliver them to customers, sometimes in as little time as one hour. Customers pay the person who makes the delivery a delivery fee, and Instacart gives them a commission. Because it doesn’t have to invest in fulfillment centers and delivery vehicles, Instacart expects that it can undercut Amazon.com Inc. and other rivals on grocery delivery.

By ordering at Instacart.com or via the Instacart mobile app, Whole Foods customers select their ZIP code, add items to a virtual cart and then choose a delivery window — within one hour, within two hours or at a scheduled time — and check out. Instacart Personal Shoppers confirm incoming orders on their smartphones, shop for the items at Whole Foods stores and then deliver orders to customers in the specified delivery timeframe.

Whole Foods will be the first national Instacart partner to offer convenient in-store pickup. For that service, he chain’s customers use the Instacart website or app to order and, instead of designating home delivery times, they select in-store pickup.

Instacart is run by former Amazon fulfillment executive Apoorva Mehta and backed by Sequoia Capital LLC partner Michael Moritz.

“Instacart and Whole Foods Market are two companies that share a common vision to create great grocery shopping experiences,” says Mehta, founder and CEO of Instacart. “Whole Foods Market is our most-requested shopping destination.”

Whole Foods had 388 stores in the United States, Canada and the United Kingdom as of July 31.