NEW YORK (Reuters) - Billionaire Michael Bloomberg filed paperwork on Thursday with the Federal Election Commission to run for U.S. president as a Democrat, the latest sign that the former New York City Mayor is joining the crowded nominating contest.

The filing allows Bloomberg to raise money in a bid for the White House, but an aide said on Thursday that no final decision on whether he will run has been made.

Bloomberg, 77, has signaled that he plans a late-entry in the Democratic primary, suggesting he feels the field of nearly 20 candidates is vulnerable. If he enters, he will likely forgo the early states where potential rivals have been visiting for months.

Bloomberg had already registered to appear on the ballot in Alabama, Arkansas and Texas.

A separate advisor said on Thursday that Bloomberg also filed to be on the ballot in Georgia and Michigan.