MUMBAI - Two of Bollywood's biggest stars, Saif Ali Khan and Kareena Kapoor, are set to tie the knot on Tuesday in India's celebrity wedding of the year, a relative said.

Actor Khan, 42, will marry actress Kapoor, 32, at the grand Taj Mahal Palace hotel in Mumbai in a union that has long been the subject of frenzied media speculation in the movie-mad country.

"The wedding is taking place tomorrow and then we will have a reception in Delhi later on. It is a very joyous moment for our family," the bride's uncle, actor Rishi Kapoor, told AFP.

The Bollywood couple, India's answer to Brad Pitt and Angelina Jolie, have been dating for four years and appeared together in this year's spy flick "Agent Vinod".

They both come from illustrious families with established links to the movie business.

Kapoor, whose hits include "3 Idiots" (2009) and "Jab We Met" (When We Met, 2007), hails from Bollywood's foremost acting dynasty, begun by her great-grandfather Prithviraj.

Her grandfather Raj Kapoor was a cinematic legend while his brothers and a number of relatives have become well-known names in the industry. The bride's mother also appeared in films in the 1960s and 70s.

Khan became the new Nawab (Muslim prince) of the former princely state of Pataudi last year after the death of his famous cricketing father Mansur Ali Khan, better known as "Tiger Pataudi".

His mother Sharmila Tagore is an award-winning actress and his sister Soha is also in the business.

Khan, who starred in 2001's "Dil Chahta Hai" (The Heart Desires) and "Hum Tum" (You and Me, 2004), has two children with his previous wife Amrita Singh. They were divorced in 2004.

Local media reported that a private pre-wedding "sangeet" party was held on Sunday at Kapoor's Mumbai residence. She wore an ornate traditional orange dress with a golden blouse, while Khan dressed in white.