• Azerbaijan, Armenia publish preliminary peace agreement brokered by US
• South Caucasus countries have been in conflict for nearly 40 years
• Deal not yet formally signed
• Azerbaijan is demanding Armenia change its constitution
• Potential deal would transform energy-rich region

TBILISI/BAKU, Aug 11 (Reuters) - Armenia and Azerbaijan published the text of a U.S.-brokered peace agreement on Monday, pledging to respect each other's territorial integrity and formally put an end to nearly four decades of conflict.

The deal was struck in Washington last Friday, when Azerbaijani President Ilham Aliyev and Armenian Prime Minister Nikol Pashinyan met with U.S. President Donald Trump at the White House.