Switzerland has signed an agreement aimed at helping ten European Union member states transform into market economies.
The SFr1 billion ($870 million) payment to countries mainly in eastern Europe was approved by Swiss voters in 2006.
Swiss Foreign Minister Micheline Calmy-Rey and Economics Minister Doris Leuthard signed the documents on Thursday.
"Today's event is of historic significance. With the signature we are giving the go-ahead for enlargement contribution implementation and opening a new chapter in relations between our countries," Calmy-Rey said.
European Union commissioner Benita Ferrero-Waldner greeted the signing of the agreements.
"The cohesion contribution is an expression of Swiss solidarity with Europe," she said in a statement. "Switzerland realises that politically and economically it benefits from the stability, security and prosperity of an enlarged European Union.
"I count on Switzerland's support in dealing with the challenges to come in extending and strengthening our common home - Europe".
Representatives of the ten countries benefiting from the payments – Poland, the Czech Republic, Hungary, Estonia, Latvia, Lithuania, Slovakia and Slovenia as well as Malta and Cyprus – were present at the ceremony in the Swiss capital Bern.
Calmy-Rey, who also holds the largely ceremonial position of Swiss president, described the Swiss contribution as a "long-term investment", while Leuthard pointed out the opportunities for Swiss business in eastern Europe.
"We hope that the enlargement contribution will not only lead to a strengthening of economic relations between our countries. It is equally important that mutual relations are enhanced in other fields: in education, science and public health, in environmental matters, culture and politics," Leuthard said.
The Swiss contribution is to go towards security, environment and infrastructure projects. Other areas include the promotion of the private sector, health and training.
The foreign ministry said the funds were aimed at benefiting above all remote areas with poor infrastructure, but support would vary from one country to the next.
The operational implementation of the enlargement contribution – organised jointly by the State Secretariat for Economic Affairs (Seco) and the Swiss Agency for Development and Cooperation (SDC) – is due to start at the beginning of next year.
Over the past few months Switzerland has negotiated bilateral framework agreements with all the partner countries that joined the EU in 2004.
Switzerland is not a member of the EU, but the 27-nation bloc is its most important trading partner. Switzerland is also expected to make payments to Romania and Bulgaria, which joined the EU at the beginning of 2007.
swissinfo with agencies
Switzerland has been granting financial aid to countries in eastern Europe to help them transform into market economies.
As part of the second set of bilateral treaties with Brussels, non-EU member Switzerland pledged to provide SFr1 billion to ten new EU member states mainly in eastern Europe.
Under the accord, almost half the funding will go to Poland. Hungary will benefit to the tune of SFr131 million, while the Czech Republic will receive SFr110 million.
Since 1990 Switzerland has spent SFr3.5 billion on about 1,000 aid projects in eastern Europe after the collapse of communism.
So far non-EU member Switzerland has agreed 16 bilateral treaties with the 25 EU member states, including the ten countries which joined in 2004.