The US has been reviewing a growing number of foreign investments for national security reasons in recent years, with investments from China the leading targets for review, according to new data released by the US Treasury on Friday.   The disclosure contained in the annual report to Congress of the Committee on Foreign Investment in the US comes amid a number of new mergers and acquisitions out of China being submitted for review. Those include the mooted $42bn takeover of Switzerland’s Syngenta byChemChina, one of that country’s largest state-owned conglomerates, and a bid announced this week for the Chicago Stock Exchange, which has already drawn calls from Congress for a review.

 According to the report released on Friday, CFIUS received 147 notices from companies voluntarily seeking national security reviews in 2014. That number was up from 97 in 2013 and the most seen since 2008, when a record 155 notices were filed.   Less than half of those notices — 52 — were deemed worthy of a subsequent investigation on national security grounds. Just one of these transactions was rejected, while a dozen applications for review were withdrawn voluntarily by companies.