Sony and Olympus said Friday their planned medical device merger has been delayed until next year, with reports and some firms saying it was the latest corporate marriage held up by Chinese regulators.

Firms in Japan, which is embroiled in a territorial row with Beijing, have launched a string of mergers and acquisitions including blockbuster deals such as Softbank's $20 billion takeover of US-based Sprint Nextel.

But some are blaming delays in completing the deals due to holdups by China's anti-trust regulators, with home builder Daiwa House Industry saying it is delaying a planned 50 billion yen ($595 million) purchase of contractor Fujita.

A share transfer that was to happen Thursday will now be pushed back "because procedures under Chinese competition law remain in effect", Daiwa House said in a statement.

Transactions that encompass operations in more than one country often require competition regulators in different nations to sign off on the deals.

Electronics giant Sony and camera and medical equipment maker Olympus, which are planning a joint venture to develop endoscopes, said Friday the launch of their new company will be delayed until next year "because procedures in some of the countries are taking longer than expected".

An Olympus spokesman declined to comment further, but Dow Jones Newswires reported that a person with knowledge of the matter had said the pair are awaiting anti-trust approval from China and an eastern European country.

Other deals awaiting the green light from Chinese regulators include ad giant Dentsu's planned $5.0 billion purchase of Britain-based Aegis Group and reportedly Marubeni's $3.6 billion acquisition of US grain giant Gavilon Group.

Dentsu said it has received approval from seven countries including Australia, Germany and the United States, with China the lone holdout.

The Japan-China territorial dispute flared in September when Tokyo nationalised some East China Sea islands that are also claimed by Beijing, sparking anti-Tokyo protests and a consumer boycott of Japan-brand goods.

But experts said China is often slower than other countries in clearing antitrust applications, and it was uncertain if the holdup for Japanese firms was intentional.

The value of deals by Japanese firms abroad has topped $110 billion so far this year, according to data provider Dealogic, a shopping spree driven by a strong yen and limp domestic market.