HILO, Hawai'i — Wal-Mart is planning an ambitious expansion into grocery sales on the Big Island by building a new "supercenter" store with a full line of groceries on a vacant lot behind the company's existing store.

A spokesman for Wal-Mart said the company then plans to either lease out its existing store, or tear down the old store to provide more parking for the new store.

The Hilo supercenter or another planned for Kaua'i would become the first in Hawai'i.

The move by the retailing giant is being cheered by some shoppers, while others have mixed feelings.

Puna resident Kim Deerr, 37, said she shops for groceries mostly at health-food stores and the Hilo Farmer's Market, and admits she is somewhat conflicted when it comes to Wal-Mart.

She remembers when the existing Wal-Mart site was vacant pasture land. Now it is a major piece of Hilo's retailing hub, a commercial center with a food court, a Borders bookstore and a parking lot that is jammed every day.

Many of Deerr's friends boycotted Wal-Mart when it opened, but Deerr didn't. She had a new baby at the time, and Wal-Mart had the cheapest diaper prices. Now, she has another baby on the way, "and I go for cheap at this point."

Still, Deerr said she tries not to shop there because "I like smaller businesses better."

Others are delighted at Wal-Mart's plans.

"We need more stores for shopping," said Ricardo Castilan, 41. "Wal-Mart is cheaper; we're glad we have a Wal-Mart." Castilan lives in Hilo and said he stops at Wal-Mart almost nightly to pick up things for his two children.

It is that attitude that persuaded Wal-Mart to expand its operation in Hilo, which company spokesman Kevin McCall said is "a proven market for us."

The company bid on a 15.5-acre parcel of Hawaiian Home Lands immediately east of the Hilo Wal-Mart "simply because we are listening to our customers, and the customers that we've talked to have asked us for a supercenter," he said.

"People are looking for alternatives, ways to save money, and our prices have consistently been proven to be 17 to 20 percent lower than traditional grocery prices."

Wal-Mart also is planning a store with a full grocery section on Kaua'i.

The Hilo supercenter would be about 200,000 square feet, he said. The company has no firm timeline for the project yet — it has up to six months to finalize the terms of a new lease with Hawaiian Homes — but McCall said it generally takes a year to build a new supercenter after all required permits are obtained.

Wal-Mart has been the target of a campaign by the United Food & Commercial Workers Union, Local 480 to try to block the supercenter format from being introduced in Hawai'i. The union represents about 2,300 workers at local grocery stores.

The Big Island County Council earlier this year asked the county planning director to consider a plan to ban supercenters, citing the harm Wal-Mart could do to Big Island farming if the company aggressively marketed imported produce.

The county resolution will have no impact on the Hilo Wal-Mart proposal because Hawaiian Home Lands are exempt from county zoning requirements.

Wal-Mart has about 4,000 stores nationwide, including about 2,000 supercenters. McCall said the company's stores in Hawai'i are among its most successful.

Reach Kevin Dayton at kdayton@honoluluadvertiser.com.