Crain’s reports that the city has narrowed down the proposals to two, maybe three, finalists to operate a bike-share system which could add about 10,000 public bikes at 600 stations to NYC’s transportation mix:

Sources confirm two finalists: Alta Bicycle Share, based in Portland, Ore., and B-Cycle, owned by Wisconsin bicycle maker Trek, health insurer Humana and advertising firm Crispin Porter + Bogusky.

Alta did Washington’s bike-share program, among others, while B-Cycle built bike-share stations in San Francisco, Chicago and other cities.

It is unclear whether a third proposal, by BYKNYC, has been rejected. Founder Aaron Marks, a former analyst at Goldman Sachs and hedge fund SAC Capital, declined to comment on the status of the bids, as did representatives from Alta and B-Cycle. City officials anticipated short-listing three companies if their proposals measured up.

The biggest and most well-known B-Cycle system launched in Denver last year. Alta has previously teamed up with the Public Bike System Company, which launched the Bixi system in Montreal and supplies London’s Barclays Cycle Hire, on D.C.’s Capital Bikeshare. Alta declined to comment to Streetsblog on whether the Public Bike System Company is a member of their team.

The BYKNYC proposal, whose status is uncertain according to Crain’s, would differ significantly from the others:

Developed by German railroad company Deutsche Bahn, it allows bikes to be locked to any fixed structure. Users can unlock bikes by calling a phone number and entering a code. The city plan calls for installing bike racks throughout the city so that bicycles don’t end up on random street corners.

The bike-share RFP was announced last November and bids were due February 16. A pilot “street test” is scheduled to launch later this year and the full system could go live in spring 2012.

NYCDOT could not confirm the Crain’s report.