The Wall Street Journal reported that the cash from the Indian group would allow Spielberg and his associates to end their existing pact with Paramount Pictures, which is owned by Viacom's Sumner Redstone.
The agreement is expected to result in a new company that will make six-seven movies every year and give Ambani a foothold in Hollywood, which his group is strongly seeking, the paper reported.
'I would not like to comment on this, ' an official with Reliance's entertainment division told from Mumbai, when asked about the reported talks.
Ambani's Reliance BIG Entertainment had announced in Cannes last month it would make a major foray into Hollywood and fund production houses run by actors like Brad Pitt, Tom Hanks, Nicolas Cage, Jim Carrey and George Clooney.
This marked the biggest foray of an Indian entity in Hollywood's motion picture industry. Thirty films are likely to emanate from Reliance's co-financing and 10 will go into production, company officials had said.