Bloomberg takes steps to 2020 race

CONCORD, New Hampshire - New York business tycoon Michael Bloomberg has paved the way for a shot at the US presidency, registering as a candidate in the Alabama Democratic primary race before Friday's filing deadline.

Although the 77-year-old billionaire and former New York mayor has not publicly announced his run, his inclusion in a crowded field kept his options open for mounting a concerted bid to topple a fellow New Yorker, US President Donald Trump.

Analysts say a Bloomberg candidacy could do the most damage to the prospects of front-runner Joe Biden, but the former vice-president put on a brave face on Friday and said he was not worried Bloomberg would draw away centrist voters.