As Wells Fargo Bank prepares to sell about 1,800 housing units in East Palo Alto to a real-estate trust, U.S. Rep. Anna Eshoo, D-Palo Alto, has joined city officials in calling for the bank to make sure the sale doesn't spell the end of affordable housing in the Woodland Park neighborhood.

The bank, which acquired the properties last year in foreclosure, plans to sell the portfolio to Equity Residential, a national company headed by real-estate magnate Sam Zell.

East Palo Alto officials and tenant activists have been adamantly opposing the sale, arguing that allowing one buyer to acquire the entire portfolio would leave the area vulnerable to redevelopment and would threaten the city's affordable-housing stock.

The properties were previously owned by Palo Alto-based company Page Mill Properties, which infuriated tenants by raising rents and filing about a dozen lawsuits against the city, challenging its rent-control laws.

Despite the city's protests, the bank indicated in a letter to the City Council last week that it plans to proceed with the sale to Equity, a sale that's expected to be finalized in October.

Rep. Eshoo, whose congressional district includes East Palo Alto, wrote in a letter to Wells Fargo CEO John G. Stumpf that she is "very concerned about the fate of these properties because there will be a profound and lasting impact on the community of East Palo Alto and my Congressional District.

"At present, the region suffers from an inadequate inventory of decent, safe and affordable housing," she wrote.

East Palo Alto has officially requested that the bank halt its sale until the city releases certificates of "maximum allowable rent" for each unit of affordable housing.

City Manager M.L. Gordon also requested in an Aug. 19 letter to Wells Fargo that the bank, as a condition of sale, require the buyer to provide written assurance that it will "abide by and conform to the requirements" of the city's affordable-housing laws.

But bank officials argued in a recent letter to the city that Equity is well qualified to offer the residents of East Palo Alto a "better quality of life" than they have experienced historically.

Wells Fargo Senior Vice President David Ash and Vice President Robert Maddox said the buyer would have the "capital, personnel and incentive to provide monetary and non-monetary support to the community overall."

The City Council last week agreed to send the bank another letter, reiterating its request that Wells Fargo not sell all the properties to one buyer. The council also called on the area's religious, political and civic leaders to petition Wells Fargo to reconsider the sale.

In her letter, Rep. Eshoo wrote that her "hope is that along with community leaders, residents and advocates, residents will have protections and East Palo Alto will continue to be an affordable community for generations to come."