The phrase "a major agreement" is correct and usable in written English.
You can use it when referring to a significant or important accord or contract between parties.
Example: "The two countries reached a major agreement on trade that will benefit both economies."
Alternatives: "a significant pact" or "a substantial accord."
"The trans-Pacific partnership is a major agreement involving some of Australia's most important trading partners.
Rite Aid already has a major agreement with 1199 to furnish most of its members with nonmaintenance prescriptions, like antibiotics.
American Express was the first company to sign a major agreement, capturing the largest space in the city -- 175,000 square feet at 400 Atlantic Street.
From that post he was a major player in the negotiations over the Nafta accord and was architect of a major agreement involving German reunification.
Chief of state: President Ezer Weizman Head of government: Prime Minister Benjamin Netanyahu The year 1997 began with a major agreement between Israel and the Palestinians.
A major international agreement, a regional agreement, and a multitude of pandemic plans put into place since 2005 have set the stage for the events of the past few weeks.
The FCIC panel failed to reach a majority agreement, with the major report signed off only by its Democrat members.
Firstly, agreement was reached on the European arrest warrant, a major, sensitive agreement which must be seen as an initial step, to be consolidated by a broader, further-reaching political and institutional project bringing further integration.
We've just completed a major labor agreement with our 15,000 unionized front-line people, which was long overdue.
C2 Cisco and BellSouth Talks Cisco Systems, the leader in Internet data network equipment, plans to announce a major development agreement today with the regional telephone company BellSouth.
