``We are ready to participate in all nine sectors, but partially and conditionally, on the basis of voluntaryism,'' Chinese ambassador Wang Yusheng to APEC, told a press conference.

He said APEC strongly emphasised the principle of voluntary participation. He said the trade liberalisation package being discussed was called Early Voluntary Sectoral Liberalisation (EVSL). ``You must not forget that it is voluntary,'' he said.

He said that APEC senior trade officials meeting in Kuantan were heading towards a ``credible agreement'' on the nine industry sectors under discussion.

Leaders from the 18- member economies of APEC agreed at last year's summit to open trade in nine sectors on a fast track basis followed by another six sectors at a later date.

This was to help acceleratethe longer-term programme of making the economies tariff free by 2010 for developed countries and 2020 for developing economies.

Asked if a consensus was emerging on the nine sectors, Wang said: ``It seems to be, gradually.''

He said that to get cooperation from members in getting an agreement, they had to recognise the diversity in the grouping and collectively set a target.

He said decisions should be on the basis of APEC principles of flexibility, gradualism and open regionalism.

``In the spirit of APEC approach, I am optimistic (of an agreement),'' Wang said.

Asked if the talks, stalled twice in the last few months, were facing any crisis, he said: ``I don't think any of it is critical. There are some differences -- just because of the diversity there are some differences of opinion.''

Officials said on Sunday they had achieved a breakthrough towards an agreement on lowering tariffs and opening up trade in the nine sectors by allowing for greater flexibility in implementing tariff cuts.

Atimetable for cutting tariffs and opening up trade worth some $1.5 trillion was held up at a meeting of trade ministers in June due to opposition, largely from Japan.

The ministers set a September deadline for the finalisation of the package, which would include list of products, the tariff levels at the end of the process and the date by which the package will be implemented.

The nine sectors are environmental goods and services, fish and fish products, forest products, medical equipment and instruments, telecommunications mutual recognition agreements, energy, toys, gems and jewellery and chemicals.

Another six sectors are to be targeted for liberalisation at a later date.

Leaders of the 18- member economies will meet in Kuala Lumpur in November to approve the trade liberalisation package.

APEC groups Australia, Brunei, Canada, Chile, China, Hong Kong, Indonesia, Japan, Malaysia, Mexico, New Zealand, Papua New Guinea, the Philippines, Singapore, South Korea, Taiwan, Thailand and the UnitedStates.

Russia, Peru and Vietnam will become members in November.