LOS ANGELES — Two sisters who ran a Los Angeles toy company were sentenced Tuesday to more than three years in federal prison for their role in helping launder money for Colombian drug traffickers.

Prosecutors had recommended 15-month sentences for Meichun Cheng Huang, 58, of Irvine, and Ling Yu, 53, of Arcadia, who both pleaded guilty last year to one count of conspiracy to structure currency transactions.

U.S. District Judge S. James Otero sentenced the sisters to a longer prison term, noting the scheme lasted for 10 years and he believed they knew the money was coming from drug cartels.

"They knew exactly what they were doing," Otero said. "It was just too profitable to turn away from."

The company, Angel Toy Corp., also was ordered to forfeit $1 million and pay a $200,000 fine.

Attorneys for Huang and Yu maintained their clients weren't aware drug cartels were funneling money into their business, but each woman apologized for their actions.

"I made a mistake," Yu told the judge through a translator. "I am willing to take all the responsibility for what I did."

The complex scheme involved the deposit of drug money to Angel Toy's bank accounts in exchange for Colombian pesos via the sale and shipment of the company's toys. More than $8 million was funneled into Angel Toy's bank accounts over a four-year period, and each deposit was for less than $10,000 to avoid raising suspicion, authorities said.

Federal prosecutors said the toy company served as a financial conduit for the drug cartels in a scheme commonly known as the black market peso exchange. The scam allows middlemen to handle transactions between drug dealers and others who want to buy U.S. dollars outside the legitimate banking system to avoid taxes and import fees.

Large amounts of cash were dropped off by couriers at Angel Toy's downtown headquarters, broken down into smaller amounts and deposited into company accounts.

The money was then used by a Colombian importer to purchase teddy bears and other stuffed animals. These toys were sent on to Colombia, where the importer sold them and gave the proceeds, in pesos, to the drug traffickers, authorities said.

"There is simply no reason why you would do business like think unless you are moving funds from illegal activity," said Assistant U.S. Attorney Sarah Levitt. "There are too many red flags here."

Lawyers for the sisters spoke of their charitable work and devotion to their family in court documents. Otero was apparently swayed by their pleas because he had initially sentenced Huang to 47 months in prison and reduced it by 10 months when he dealt separately with her sister Yu.

Otero said it was difficult to accept that neither Huang or Yu knew drug cartels were using the company to launder money. He noted the company drew more than $450,000 in cash during December 2005 alone.

"It's pretty obvious what was going on," Otero said.