German chip maker Infineon said on Monday it had won a contract from the U.S. government to supply security chips for an electronic passport system. Infineon said the United States was planning to start issuing the passports to citizens by the end of the year, with about 15 million electronic passports in the first year.

"Infineon will supply chips for several million passports, but not for all 15 million," an Infineon spokeswoman told Reuters.

The company declined to give any further details about the size and value of the contract.

Infineon is the first and currently the only supplier for these kind of security chips contracted by the U.S. government, the company said.

Countries such as Germany, Hong Kong, Norway and Sweden are also using Infineon's security chip for their electronic passport systems.

Infineon said that out of almost 300 million Americans an estimated 67 million held a U.S. passport. In Germany there were about 24 million passports.

Worldwide there are currently about 900 million passports, with an estimated 125 million being issued or exchanged every year, the company said.

The security chip, which stores the passport-holder's name, date of birth, issue date and picture, can be read electronically by a scanner.