"I will be collaborating with Usher and Dido, but it is not for my next album as everyone is saying. It is for some other project, the details of which I can't reveal yet," Rahman told IANS in a telephonic interview from London.
"I'm concentrating on my world tour right now, and my work on the collaboration will start after it is over," added the composer who is rehearsing for his European performances in London.
Rahman, who has worked with music giants like Andrew Lloyd Webber, Kylie Minogue, Nicole Scherzinger of Pussycat Dolls, and over 60 international musicians including Quincy Jones and Lionel Ritchie in a charity single, is touring the US and Europe as part of his "Jai Ho Concert: The Journey Home World Tour" concert.
The 44-year-old has already covered many places in the US, including New York, New Jersey, Washington DC and Chicago among others. The next leg of the tour will be in Britain and different European countries.
Rahman, who shone on the global arena with his work in "Slumdog Millionaire" that fetched him double Oscars, says he has put his Hollywood ventures on hold for the time being.
"I did get offers from a number of directors in Hollywood, but right now I'm not taking anything because I don't have the time due to my world tour. So I have postponed that for some time."
Rahman, who cancelled the North American leg of his "Jai Ho" concert after a lighting rig collapsed in Detroit before the show, is rehearsing for his next tour, which includes concerts in Zurich, Paris, Amsterdam and then London.
One of the most downloaded composers in Britain, Rahman will perform July 23 at LG Arena in Birmingham, to be followed by shows in the two biggest arenas in London - O2 and Wembley on July 24 and July 25 respectively.
Victory Entertainments is promoting his concerts in Britain.
Apart from the Oscars, the ace composer, also known as the "Mozart of Madras", has won a BAFTA Award, a Golden Globe and two Grammy Awards.
Asked what makes him a global celebrity, Rahman said: "Well it's tough for me to tell you what it is. I think it's just about the timing. First, 'Slumdog Millionaire' happened, then all the awards followed and then one thing led to another."
Before making it big in the global arena, Rahman infused freshness in Indian film music with his amazingly good compositions in "Roja", "Bombay", "Rangeela", "Lagaan" and "Jodhaa Akbar" and his work was appreciated with four National Film Awards.
Back home he has two projects to look forward to - Pawan Kalyan-starrer Telugu film "Puli" and director Shankar's forthcoming Tamil science-fiction "Endhiran" that has Rajnikant and Aishwarya Rai in lead roles.
When asked how he manages everything - from Hindi to regional to international projects, the maestro said: "It is not such a problem managing everything. It goes on simultaneously. Also, I have a very hardworking team, which is always there to help me."
It's not just Rahman who has a musical mind in his family; son Amin is also showing signs of his father's talent. The six-year-old sang a song in the Hollywood film, "Couples Retreat".
So will Rahman encourage his son to get into the industry?
"Right now, we can't say anything. He is too young. It all depends, when he grows up," said the ace composer.