FACTBOX: Friction between neighbors Venezuela, Colombia

(Reuters) - Venezuelan President Hugo Chavez on Sunday raised tensions with Colombia over a U.S. troop plan, accusing his neighbor of sending an army patrol over their Orinoco River border and ending a Colombian gasoline subsidy.

Chavez made his remarks on the eve of a regional summit in Ecuador, where the persistent Washington critic will try to fuel opposition to a Colombian deal to allow U.S. troops more access to seven of its military bases.

Insults, threats and diplomatic protests are common between leftist Chavez and his conservative Colombian counterpart, Alvaro Uribe, but the two leaders usually quickly make up.

Following are some key facts about the two neighbors and their joint history:

* Venezuela and Colombia's share a 1,375-mile (2200-km) border and hundreds of years of volatile history. After both were liberated from the Spanish by Venezuelan freedom fighter Simon Bolivar in the 19th century, the two countries were the center of a short-lived nation known as Gran Colombia that also included Ecuador and Panama.

* Colombia's four-decade internal conflict has for years spilled over into Venezuela, but the ideological closeness of Chavez and the FARC Marxist rebels fighting Bogota has increasingly led Uribe's government to accuse the Venezuelan of supporting the guerrillas.

* Chavez, 55, often responds to such accusations not only with diplomatic reprisals but torrents of abuse against Uribe, who he has called a "mafioso" linked to right-wing paramilitary fighters. On Wednesday, he accused Uribe of "spitting lies" about him. Uribe's government has threatened to take Chavez to international court, alleging he supported genocide by leftist Colombian rebels.

* Chavez's recall of his diplomats from Colombia in July was the third such decision since 2005, when tensions rose over the arrest in Caracas of a FARC leader in a Colombian-led police operation.

* The two countries raised the specter of war last year after a Colombian bombing raid on a guerrilla camp in Ecuador sparked troop movements from Quito and Caracas. Chavez cut diplomatic relations with Bogota and threatened to stop cross-border trade.

* Despite the friction, trade has blossomed in recent years to $7 billion in 2008. Flush with cash from a boom in its principal export, oil, Venezuela has bought Colombian farm produce and cars, in exchange for fuel and chemicals.

* In calmer times Chavez and Uribe have displayed a rapport, exchanging hugs and jokes and striking a cross-border natural gas pipeline deal.

(Reporting by Frank Jack Daniel; Editing by Eric Beech)