In a statement, CTA says it expects to invite bids later this year for the 7000 series fleet, which will replace life-expired rolling stock which is nearing or over 30 years-old. An initial order for 200 vehicles is planned which will be funded through a combination of federal and local funds.

CTA says it will include a US employment provision in the tender, which will ask bidders to specify the number and type of jobs they will create in the United States through the production of the new trains. It will also ask bidders to outline their recruitment and workforce training plans.

"Our goal is to help create as many US job opportunities as possible, and to encourage local opportunities wherever possible," says Chicago mayor Mr Rahm Emanuel. "Additionally, we believe this will increase competition among bidders and result in the best prices and highest quality product for CTA customers, which is essential in building a world-class transit system."

CTA issued a tender for the 7000 series contract early last year but this only attracted two bids.