LOS ANGELES, Calid.–City Controller Wendy Greuel said today she subpoenaed three cell phone companies and accused them of failing to comply with repeated requests to turn over five years of city cell phone bills.

Greuel said she employed the rarely used power after AT&T Mobility, T-Mobile and Sprint Nextel Corp. declined her requests or asked for extensions over a period of several months. Verizon handed over the requested bills last week, the controller said.

Greuel, who is running for mayor, said copies of the bills are necessary to complete a larger investigation into whether the companies performed contractual duties to analyze the city’s phone bills for ways to save money.

“Today, I am sending a clear message that stall tactics will not be tolerated,” Greuel said during a morning news conference. “It’s absurd that businesses doing business with the city of Los Angeles want to deny the city’s access to cell phone bills. I urge AT&T, T-Mobile and Sprint Nextel to hand over the those bills and stop acting as though they have something to hide.

“These are our bills. There should be no reason that we would not receive them,” Greuel added.

A May 2011 audit by the controller found that decentralized oversight of contracts by individual city departments caused the city to pay more for cell phone service than necessary–to the tune of $375,000 to $1 million.

In a previous audit, Greuel called for a 60 percent reduction in the nearly 12,000 cell phones used by city employees. The city could save $1.2 million by providing stipends to certain employees who use their own cell phones for city business instead of contracting with wireless phone companies.

Greuel said the companies have until Jan. 14 to hand over the requested documents. Under city law, failing to comply with the subpoenas is a misdemeanor offense punishable by a fine of up to $1,000 or six months in a county jail.