Madrid, April 21 President Pratibha Patil on Tuesday stressed India's interest in boosting relations with Spain, where she became the first Indian head of state to make an official visit.

Bilateral trade had increased rapidly, rising to $4.5 billion in 2008, Patil said during a visit to Spanish parliament after attending official welcome ceremonies with King Juan Carlos.

India was also interested in cooperation in other sectors, including renewable energies and agriculture, Patil explained.

Spanish Parliament President Jose Bono said the two countries were united in their faith in freedom and refusal to yield to terrorist threats.

Bono was referring to violent Basque separatism in Spain and the Mumbai attacks that killed more than 170 people in November.

King Juan Carlos and Queen Sofia welcomed Patil and her husband Devisingh Shekhawat in front of El Pardo Palace.

The two heads of state then listened to national anthems, inspected a honorary guard and watched a military parade.

After visiting parliament, Patil had lunch with the royal couple, who visited India in 1982.

Patil was also due to meet Prime Minister Jose Luis Rodriguez Zapatero and Spanish entrepreneurs during her visit.

The visit was described as opening a new phase in political, economic and cultural relations between Spain and India.

Spain, which is not a member of the Group of 20 (G20) but participated in its recent meetings in Washington and London, was expected to seek G20 member India's support for its permanent integration into the forum.

On Thursday, Patil was scheduled to continue her European tour to Poland.