CO-OPERATION between mainland China and Taiwan was given a major boast yesterday as representatives from the two sides concluded a two-day summit by signing historic agreements. Mr Wang Daohan, chairman of the Beijing-based Association for Relations Across the Taiwan Strait (ARATS), praised the summit as a ''historic moment'' in cross-straits relations. He added that it was very important for the future development of relations. And before his departure, Mr Tang Shubei, ARATS vice-chairman, told reporters: ''See you next time in Beijing or Taipei.'' Mr Koo Chen-fu, chairman of Taiwan's Straits Exchange Foundation (SEF), said the meeting had opened a new era in removing antagonism between the two sides after 44 years of separation. ''We have now built a bridge that is a milestone in future systematic exchanges between the SEF and ARATS,'' Mr Koo said. ''No one can say that we have not achieved any results. We have already achieved the basis for further discussion. ''We have laid a good foundation for the future development between both sides. And this indeed is of very great significance.'' The agreements were signed yesterday morning at the Neptune Orient Line Building when Mr Koo led Mr Wang into the conference room at 10.40 am. The two leaders sat down behind a long table and their wives and the other SEF and ARATS members looked on from behind. In a gesture to symbolise the equal footing of the two parties, the two leaders took the seat in turn with Mr Wang going first. The ceremony ended at 10.53 am with a champagne toast. Three documents signed yesterday covered formal channels of dialogue between SEF and ARATS, verification of documents such as wills and contracts and compensation of lost registered mail between Taiwan and the mainland. The fourth document described in broad terms the achievements of the summit and agreed to jointly develop energy and resources and complementary visits of young people, journalists, artists and scientists from both sides. The document - tentatively called the ''Wang-Koo Meeting Joint Accord'' - also provided procedural guidelines on repatriation of illegal immigrants, settlement of fishing disputes, protection of intellectual property, mutual assistance from the judiciaryof both sides and co-operation in cracking down on marine crime. It further stated that the two sides were willing to resolve their differences on economic matters such as the protection of Taiwanese investment on the mainland and the possibility of a joint economic conference this year. A junior level ARATS delegation is expected to travel to Taiwan next month to continue talks on cross-strait exchanges. It was understood that more mainlanders would benefit from the ability to receive inheritance from their Taiwan relatives and in applying for visas to travel to the Kuomintang stronghold. On the other hand, the pact provided greater guarantee for Taiwanese in areas such as mail communications, adoption of their mainland relatives and verification of commercial documents. While Mr Koo acknowledged that differences remained, he stressed that the talks had already laid a ''solid groundwork'' for future discussions. Meanwhile, the joint accord was criticised by the Democratic Progressive Party (DPP), Taiwan's largest opposition party, which accused the SEF of losing much ground to ARATS during negotiations. The DPP, which staged a brief protest outside the talks venue before the signing ceremony said talks with Beijing were futile unless the Taiwan public were allowed a referendum to decide their national identity. ''I think the mainland has made more gains than we did through this talk,'' said Ms Tracy M. H. Tsai, a DPP parliamentarian.