The phrase "announced a contribution" is correct and usable in written English.
You can use it when referring to someone making a public statement about their donation or support for a cause, project, or organization.
Example: "The company announced a contribution to the local charity to support their community programs."
Alternatives: "declared a donation" or "revealed a gift".
So far, Kuwait has announced a contribution of $180 million to the transitional government.
Yale University today announced a contribution of $160 million by Edward P. Bass '67 toward the renovation of the Peabody Museum of Natural History.
This year, Hobart City Council announced a contribution of $700,000 for the next three years of the festival, with the state government handing over $2.1m for 2016 alone (a hefty increase from the $3m bestowed on the festival for the three years prior).
The Times reported that Laurie M. Tisch, a chairwoman of the Whitney Museum, announced a contribution of half a million dollars to the Justice Fund, from her sale of a Max Weber painting, saying of Gund, "I was moved by her passion".
São Paulo, January 2011 – The Urban Fish (www.peixeurbano.com), pioneer and leader in collective purchases in Brazil, announced a contribution of the most important venture capitalists in the United States, Benchmark Capital, and a major venture capital firms in the country, Monashees Capital for Series A round of investment made in the last quarter of 2010.
The Gulf state's ruling emir, Sheikh Sabah al-Ahmed al-Sabah, promised $500 million in new aid, while the United States announced a contribution of $380 million.
IRISH AID contributes K80 million to Malawi to combat malnutrition [PDF] Lilongwe, 07 November 2008: Irish Aid announces a contribution of K80 million to the Government of Malawi, through UNICEF, in support of the Government's efforts to eliminate micronutrient malnutrition.
He later announced a $42,000 contribution to her campaign, the maximum allowed by law.
In May, Mr. Black and his wife announced a $48 million contribution to a new visual arts center at Dartmouth College, Mr. Black's alma mater.
In part to allay criticism of its profits and bonuses, Goldman announced a $200 million contribution to its foundation, which promotes education.
Google.org President Jacquelline Fuller today announced a $2 million contribution to the Wikimedia Endowment.
