WRAPUP 10-Clinton gives herself loan, vows to fight on

* Obama campaign sees finish in sight

* Clinton promises to keep fighting

* Clinton loans campaign $6.4 million (Adds details, Plouffe quote)

By John Whitesides, Political Correspondent

WASHINGTON, May 7 (Reuters) - Barack Obama took a commanding lead in the Democratic presidential race on Wednesday, but Hillary Clinton said she would fight on after loaning her campaign $6.4 million to keep it alive.

Obama's big win in North Carolina and Clinton's slim victory in Indiana widened his advantage in their battle for the right to face Republican John McCain in the November presidential election with just six contests remaining.

The results left the cash-strapped Clinton campaign with few opportunities to halt Obama's march to the nomination. But the New York senator remained defiant.

"I'm staying in this race until there is a nominee," Clinton told reporters after a campaign rally in Shepherdstown, West Virginia, which holds the next contest on Tuesday.

Clinton dipped into her personal fortune again in the past month to try to keep pace with Obama, putting $5 million into her campaign chest on April 11 and $1.4 million over the past week, aides said. It was the second time she used her own money to fund her White House bid.