UPDATE 3-United seals Latin American tie-up with carriers Avianca and Copa

(Adds financial details, context, shares)

Nov 30 (Reuters) - United Continental Holdings Inc has finalized a three-way joint venture with carriers Avianca Holdings SA of Colombia and Copa Airlines of Panama, giving the No. 3 U.S. air carrier a stronger foothold in Latin America where travel demand is rising.

Under the deal announced on Friday, United said it would provide a $456 million term loan to cash-strapped Avianca's top shareholder, Synergy Group Corp.

Like its main U.S. rivals, United has been eyeing untapped potential for leisure and business travelers in Latin America, where many still travel long distances by car and bus.

United, Avianca and Copa are already codeshare partners and Star Alliance members, but a joint venture will allow them to plan routes and connections together and share revenues on those routes.

"This agreement represents the next chapter in U.S.-Latin American air travel," United President Scott Kirby said.

United's deal with Avianca, long in the works, had undergone significant legal back-and-forth after the Colombian flagship carrier's No. 2 shareholder Kingsland Ltd tried to halt negotiations between United and Synergy. The parties eventually came to an agreement.

The joint venture is subject to regulatory approval in the United States and several jurisdictions in Central and South America.

The Wall Street Journal first reported on Friday that the deal between United, Avianca and Copa was nearing completion.

Shares in United closed 1.7 percent higher Friday at $96.70. (Reporting by Ankit Ajmera in Bengaluru and Tracy Rucinski in Chicago; additional reporting by Marcelo Alonso Rochabrun in Sao Paulo and Julia Symmes Cobb in Bogota; Editing by Shailesh Kuber and Tom Brown)