该产品的市场份额在美国占一半以上，翻译成英语

The product's market share in the United States accounted for more than 50%.
或the product shared more than 50% portion in the united states market。
翻译没有完美的版本希望我的能给你一些提示。

The product takes over half of the markte shares in the US.

This product takes more than half market share in US.

The products take more than 50% market in USA.