Republican presidential candidate Mitt Romney on Friday disclosed selling his stakes in dozens of companies over the past year, including investments in several overseas companies that might have undermined his increasingly tough campaign vows to create American jobs and crack down on foreign competitors.

In Ohio and other battleground states, Romney is making an aggressive appeal to working-class voters by promising to punish China for alleged currency ma­nipu­la­tion and violations of intellectual property protections and other laws. Criticism of President Obama’s handling of trade issues also is part of Romney’s offensive.

The new disclosure report shows that Romney has sold all of his private, independently owned stock in foreign companies. But he still has a stake in foreign companies through investments in Bain Capital, the private equity firm he founded in Boston in 1984. Citing Bain confidentiality requirements, Romney has declined to disclose the nature of those investments.

The sales included shares in Chinese real estate and educational firms and in Wal-Mart de Mexico, which has come under scrutiny amid bribery allegations. Romney also sold stock in dozens of name-brand U.S. firms, including McDonald’s, Google, Apple and JPMorgan Chase, the records show.

Campaign spokeswoman Andrea Saul said that the Romney family’s assets “are managed on a blind basis” by a Boston-based attorney. “They do not control the investment of these assets, which are under the control and overall management of a trustee,” Saul said.

If elected, Romney would be among the wealthiest individuals ever to win the presidency, with a net worth estimated in the report of up to $255 million. The overall figures are little changed from what Romney reported last year .

In records submitted to the Office of Government Ethics, presidential candidates must provide only broad value ranges for their holdings, making determination of a precise net worth impossible. Forbes magazine recently estimated Romney’s net worth at $230 million, while his campaign characterized the amount at $190 million to $250 million.

Obama and the first lady, Michelle, reported assets worth between $2.6 million and $8.3 million in a personal finance disclosure filed last month. The couple had up to $1 million in a JPMorgan asset management account; $1 million to $5 million in U.S. Treasury notes; and a mortgage of between $500,000 and $1 million on their Chicago home.

Romney’s personal wealth has become a regular point of debate in the 2012 presidential contest, in part because of attacks by Republican primary opponents and the Obama campaign on Romney’s history as a leveraged buyout specialist. Romney has defended his private equity career as a way of creating jobs and has accused Obama of attacking free markets.

Romney has several holdings linked to major political donors, including stock in Marriott International, where Romney served as a director. Marriott International’s chairman, J.W. “Bill” Marriott Jr., and his brother, Host Hotels & Resorts chief Richard Marriott, have contributed $1 million each to Restore Our Future, a super PAC dedicated to helping Romney win the White House. Romney also has more than $1 million invested with the firm run by hedge fund billionaire Paul Singer, who has hosted fundraisers for Romney and has given $1 million to Restore Our Future.

Romney reported receiving $189,000 in 2011 for four speeches, including $68,000 each for addresses to Goldentree Asset Management and the International Franchise Association. Romney prompted jeers from Democrats in January when he described $374,000 in earlier speaking fees as “not very much” money.

The disclosure shows that Romney’s stock sales included up to $15,000 in Wal-Mart’s Mexican affiliate, which was the focus of a New York Times report in April alleging that the Arkansas-based retail giant failed to report millions of dollars in payments to Mexican officials to aid the brand’s expansion in the country.

The new disclosure report also shows that Romney sold holdings in several companies based in China, including Hang Lung Properties, a Hong Kong real estate firm that owns properties in Hong Kong and on the mainland. The company is chaired by entrepreneur Ronnie C. Chan, who served as a trustee of the University of Southern California and as a director of several companies, including Enron at the time of its collapse.

Romney also sold stock in New Oriental Education & Technology Group, a provider of private educational services in China. The company is listed on the New York Stock Exchange and reports having more than 20,000 employees. In addition, he sold his stake in the holding company for the stock exchange of Hong Kong.

Despite the latest disclosures, much of Romney’s wealth remains hidden because of an obscure exception in federal ethics law that allows him to avoid revealing the extent of his investments.

The Romney campaign has long characterized his holdings as being managed by a blind trust. But the Romney trust does not meet federal standards for independence, meaning he is supposed to disclose all assets in that trust, including underlying holdings, according to legal experts.

Romney, however, has cited Bain’s confidentiality requirement in declining to identify his underlying holdings with the firm. His trustee, Brad Malt, a Boston attorney working for the law firm that represents Bain, said in a news briefing last year that he did not receive investment instructions from Romney but that he sold some holdings that he thought might conflict with Romney’s views as a presidential candidate.