Beijing's leading official on Taiwan affairs started a six-day trip to the island on Wednesday that will include business deals and visits to the pro-independence heartland.

Chen Yunlin, president of the mainland's Association for Relations Across the Taiwan Straits, arrives at Taoyuan airport near Taipei for a six-day visit to the island on Wednesday. [Photo/AFP]

Chen Yunlin, leading a delegation of about 20 mainland companies, landed at an airport near Taipei amid tight security while dozens of protesters rallied and scuffled briefly with police.

Chen, president of the mainland's Association for Relations Across the Taiwan Straits (ARATS), attended a business forum and a dinner banquet in Taipei later on Wednesday.

Chen urged the Taiwan authorities to review their policy of restricting mainland investment to help more mainland firms to invest in the island.

Mainland investment in Taiwan stood at only US$153 million in 73 projects, in stark contrast with more than 80,000 Taiwan-funded projects with a total investment of US$51.7 billion on the mainland.

Taiwan leader Ma Ying-jeou said on Wednesday at a separate business event in Taipei that allowing more mainland investment in Taiwan will help generate more job opportunities to benefit the island's economy.

Chen's trip began in Taipei, the power base of Ma, who has been pushing for closer economic ties with the mainland since taking power in May 2008.

But in contrast to his previous visits, Chen will spend most of his time in southern Taiwan, where the main opposition Democratic Progressive Party (DPP) holds most political power.

Pro-independence activists have promised protests, but the DPP will not be participating.

The party's departure from its past practices appears to reflect recognition that many Taiwan people, including those in the south, believe that Ma's policy of embracing the mainland economically is paying financial dividends.

Chen's entourage on this trip includes more than a dozen high-level business people and a series of deals are anticipated.

On Thursday, he is due to leave for Kaohsiung, the island's largest city in the south, where radical pro-independence groups have vowed to stage mass protests wherever he goes.

In Kaohsiung, DPP stalwart Mayor Chen Chu is expected to attend a gala luncheon uniting local business leaders with Chen Yunlin's delegation.

In a related development, Yang Yi, spokesman for the Taiwan Affairs Office of the State Council, said on Wednesday that the Chinese mainland and Taiwan are expected to conclude negotiations on a cross-Straits investment protection agreement this year.

Efforts were being made to ensure the agreement be signed during the meeting of the heads of ARATS and SEF, he told a regular press conference.

The seventh-round meeting of heads of ARATS and the Straits Exchange Foundation will be held this year, but no exact date has been disclosed, Yang said.

Cross-Straits trade volume totaled $145.37 billion last year, a rise of 36.9 percent year-on-year. The figure included $115.69 billion of Taiwan exports to the mainland with a year-on-year rise of 20.2 percent.