Divorce talks between Tiger Woods and Elin Nordegren have become ugly, major US newspapers have reported.

Nordegren has ramped up her financial demands, requesting the golf great pony up an estimated US$750 million ($1105 million), the Chicago Sun-Times and New York Times reported yesterday.

After starting out fairly civil, the divorce negotiations "have turned extremely testy," the newspapers reported.

Nordegren also refuses to sign a lifetime "confidentiality clause", which would prevent her from writing a book or doing any interviews related to the collapse of the couple's marriage.

She also reportedly wants full custody of their two kids, even though it was first believed they would share joint custody.

Nordegren has spent a lot of time away from her husband in recent months. She went to Arizona alone for nearly a week recently and took the kids to Sweden while Woods played golf.

RadarOnline reported Nordegren is renting a house just over a kilometre away from the Florida home she once shared with Woods. The kids get to sleep over at Woods' house.

Woods, meanwhile, announced this week that he was adding the British Open in July to his golfing schedule.