By Bob Sechler

Chicago city officials said Friday that it has received 16 responses from companies and investment groups interested in bidding on a long-term lease to operate Midway Airport for profit.

The city plans to review qualifications of the various entities and then seek formal bids from those deemed to have the necessary expertise and financial wherewithal. Mayor Rahm Emanuel has stressed that the city might not go through with a deal, saying he simply wants to "test market interest" in a Midway lease of under 40 years.

Global Infrastructure Partners LLC, which owns the U.K.'s Gatwick airport, is among the interested parties. Grupo Ferrovial SA (FER.MC), which owns Heathrow Airport in London, and Australia-based global investment firm Macquarie Group Ltd. (MQG.AU), also are involved in an investment consortium that has expressed interest in Midway. Chicago had asked interested bidders to respond by Feb. 22.

"The response generated ... is encouraging and provides the city with a sense of the strong level of interest in a potential lease," Chicago Chief Financial Officer Lois Scott said in a prepared statement.

A previous, high-profile effort to privatize Midway--negotiated under the administration of Mr. Emanuel's predecessor, Richard Daley--fell apart amid the financial crisis in early 2009, when the investors were unable to obtain financing.

Under that deal, the private operators would have run Midway under a 99-year lease in exchange for a $2.5 billion upfront payment.

Chicago city officials said Friday that at least one member of the investor group that won the previous bid-- John Hancock Life Insurance Co.--has expressed interest again.

Regardless, Mr. Emanuel has said any Midway lease approved under his watch must be significantly shorter and include a continuing revenue stream for the city, in addition to upfront money.

He initially opposed renewing the Midway privatization effort when he took office in May 2011 but opted to revive it in December, partly because of the perceived success that Puerto Rico officials had in attracting investors interested in running Luis Munoz Marin International Airport in San Juan.

Under the Puerto Rico deal--which is pending final approval by the Federal Aviation Administration, as well as financial close--private operators plan to invest more than $1 billion in the San Juan airport, including $615 million upfront in a leasehold fee.

The investment consortium, comprised of infrastructure-investment company Highstar Capital and Mexican airport operator Grupo Aeroportuario del Sureste SAB de CV (ASR, ASUR.MX), also would pay Puerto Rico a percentage of revenue over the 40-year life of the lease.

Airport privatization is widespread in Europe and Asia, but the effort in Puerto Rico is the only sizable U.S. project in an advanced stage.

Write to Bob Sechler at bob.sechler@dowjones.com

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