The agreements resolve - at least for now - long-running conflicts over government aid provided to U.S. planemaker Boeing Co and Europe's Airbus, allowing the United States and Europe to focus more countering China, which is rapidly developing its own commercial aircraft industry.
The World Trade Organization had found the world's two largest planemakers received billions of dollars of subsidies in a pair of cases dating back to 2004, and ultimately allowed both sides to impose billions of dollars in punitive tariffs.
Here are highlights of the feud that has spawned thousands of pages of rulings, triggered threats of tit-for-tat tariffs on goods from plane parts to whisky and left both sides claiming victory while racking up an estimated $100 million in costs.
The U.S. seeks talks with the EU and Airbus host nations Britain, France, Germany and Spain over alleged unfair subsidies via government loans. Washington terminates a 1992 U.S.-EU agreement covering support for Airbus and Boeing. The EU files a complaint on U.S. aid for Boeing.
The WTO launches twin probes into public support for Boeing and Airbus after bilateral negotiations fail.
Airbus announces a new A350 jetliner for which it will seek further government loans from host nations.
The WTO issues an interim ruling that some European aid provided to Airbus violated a ban on export subsidies - a type of aid deemed most harmful and therefore automatically banned.
The WTO demands a halt to unfair aid for jets including the Airbus A380 superjumbo. It says some government loans for the jet amount to "prohibited" export subsidies. But it rejects a U.S. request to include aid for the newer A350 in the case.
The EU loses an appeal and is given until December to comply. However the WTO drops its finding that the A380 loans are in the "prohibited" category, softening its earlier ruling.
A separate WTO panel partially backs the EU in its counter-case alleging $19 billion of support for Boeing from the U.S. government, NASA and various states and municipalities, and rules against aid for Boeing worth at least $5.3 billion.
WTO appeal judges broadly uphold the ruling against U.S. support for Boeing. Both sides say they have complied with WTO rulings, while accusing the other side of failing to do so.
Boeing announces the twin-engined 777X and agrees to build it in Washington state shortly after the local legislature agrees $8.7 billion in new aerospace industry tax breaks.
The EU opens a second front in the trade battle by launching a separate complaint against the 777X tax breaks granted by Washington state and this time chooses a faster, all-or-nothing approach by targeting them purely as "prohibited" subsidies - without the usual fallback of a second, softer claim.
After a year-long lull in the main dispute, the WTO says the EU failed to comply with its earlier rulings on Airbus. It also agrees for the first time to target aid for the new A350 but rejects U.S. calls to put this in the "prohibited" category.
In November, the WTO rules tax breaks surrounding the development of the Boeing 777X - the subject of the EU's second case - did fall into the more severe "prohibited" category.
WTO appeal judges reverse that "prohibited subsidy" ruling on 777X, bringing an abrupt halt to the EU's second case.
In the EU's main case, the WTO largely clears the United States of maintaining unfair support for Boeing but says it has failed to withdraw the earlier Washington state tax breaks. The EU appeals unsuccessfully.
In May, the WTO again rules that the EU has failed to halt all subsidies to Airbus. The United States threatens sanctions on billions of dollars of European products. Both sides enter arbitration to determine the scope of tariffs.
In March, the WTO says the United States has again failed to halt subsidized tax breaks to Boeing in Washington state. The two sides disagree widely in public over the amount of subsidy faulted by the WTO.
Both sides accuse the other of refusing to negotiate any settlement and unveil lists of billions of dollars of proposed tariffs on each others' goods.
WTO arbitrators award the U.S. the right to impose tariffs on $7.5 billion of annual EU imports. In October, Washington imposes 10% tariffs on most Airbus jets and 25% duties on products https://www.reuters.com/article/uk-wto-aircraft-tariffs-factbox-idUKKBN1WH1DZ ranging from cheese to olives and single-malt whisky.
In December, the WTO rejects EU claims that it no longer provides subsidies, prompting Washington to warn of tariffs on a wider range of European goods.
The United States announces an increase in tariffs on aircraft imported from the EU to 15% from 10%.
In March, the Washington state legislature votes to remove a contested aerospace tax break that had benefited Boeing.
In October, following delays due to the coronavirus crisis, the WTO grants Brussels permission to impose tariffs on $4 billion of U.S. goods over subsidies for Boeing.
The European Commission offers to pull back from imposing tariffs if Washington withdraws its existing tariffs.
But the U.S. Trade Representative's office says Brussels has "no legal basis" to impose the tariffs since a tax break provided by Washington State to Boeing has been repealed.
Britain, no longer part of the EU but still a large player in the dispute, decides to suspend tariffs on Boeing jets and other U.S. goods to create goodwill for separate agreement with Washington. Both the EU and U.S. snub the offer.
U.S. Trade Representative Robert Lighthizer says U.S. and Europe should cooperate in opposing future subsidies used by China to build its commercial aircraft industry.
U.S. increases tariffs on certain EU products, including aircraft parts and non-sparkling wines from France and Germany.
In March, Britain and the United States agree to suspend tariffs to allow serious negotiations to proceed.
Brussels and Washington follow suit, suspending tariffs related to the aircraft dispute for four months through July 10.
At a June summit, U.S. and EU leaders hail an agreement to resolve the dispute. It involves extending the tariff suspension for five years while pledging to tackle aerospace funding by "non-market actors" such as their new rival China.
Two days later, Britain and the United States reach a similar deal, ensuring that retaliatory tariffs remain suspended.
(Compiled by Andrea Shalal and Tim Hepher; Editing by David Evans, Keith Weir and Daniel Wallis)