"conference concluded" is correct and usable in written English.
You could use it at the end of a document to indicate that the conference has finished. For example: The conference ran for two days and provided useful insights into this year's economic trends. Conference concluded.
The news conference concluded with a long back-and-forth with Fox News about... Benghazi.
Their conference concluded with playwright Alan Bissett reading the People's Vow.
Fortunately the conference concluded with a quite profound 2 hour meditation session.
The conference concluded that such capabilities fell far short of meeting present and future needs, particularly in less-developed countries.
The tourism trade accounts for about 5percentt of the world's carbon dioxide emissions, the Davos conference concluded.
The Berlin West Africa Conference concluded, the major European countries having staked claims to their colonial expansions in Central Africa.
The Judicial Conference concluded two years ago that judges should not participate in seminars if the sponsors or underwriters were involved or likely to be involved in litigation.
In fact, both the authoritative U.S. Preventive Services Task Force and a 2006 National Institutes of Health State-of-the-Science concludede concluded that multivitamins do not offer protection against heart disease or cancer.
While the SXSW Interactive Conference concluded days ago and is likely only a faint, buzzed memory in the minds of its tech-savvy attendees, the Music side of SXSW just closed shop today.
Before the Washington Naval Conference concluded, the ship's construction was suspended in February 1922, when she was 24.2 percent complete.
But a 2013 report from the House Republican Conference concluded that although the CIA made the majority of the edits, it was State Department officials who mainly objected to language linking the incident to terrorism.
