The phrase "asserted it was" is correct and usable in written English.
You can use it when reporting someone's claim or statement about a particular situation or fact.
Example: "The scientist asserted it was necessary to conduct further research to validate the findings."
Alternatives: "claimed it was" or "stated it was".
But Mr. Dreifach said the State of New York singled out Network Associates because, he asserted, "it was the most egregious example we saw".
But with its cartoonlike characterizations (everybody from Nelson Rockefeller to Diego Rivera to William Randolph Hearst to Bertolt Brecht), it is a historical offense against the Federal Theater Project itself, reducing it to what its enemies in Congress asserted it was, a sort of agitprop factory run by a crowd of lefties.
The company has repeatedly asserted it was not at fault for the explosion and that its heat exchanger maintenance was in line with industry standards and regulations.
Rather, he asserted it was packaged with a passion that might as well define him.
They asserted it was a backdoor effort to expand legal protections for fetuses and restrict the reproductive rights of women.
At the risk of undermining your entire argument, I never asserted it was fact or anything of the kind.
Discussing their second release, Svenonius asserted: "it's like a blueprint for the destruction of the Parent Culture.
Cooper asserts, "it is an insult to humanity and a sin against God to publish any such sweeping generalizations of a race on such meager and superficial information.
McDonald's has so far prevailed in the lawsuits that have asserted it is partly to blame for its customers' bulging waistlines.
Another commentary asserted, "It is the black heart of Islam, not its black face, to which millions object".
But, Mr. Price asserted, "It's time they move beyond empathy to aggressive corrective action".
