WELLINGTON, Oct 16 (Reuters) - Jim Bolger, New Zealand's prime minister from 1990 to 1997 who helped usher in a new era of reconciliation with indigenous Maori, died on Wednesday aged 90, his family said in a statement.

Bolger had suffered kidney failure last year and had been undergoing dialysis. He died surrounded by his wife Joan, nine children and 18 grandchildren, the statement said.

Bolger entered parliament in 1972 and became leader of the National Party in 1986 before becoming prime minister in 1990 when the party took power. He retired from politics in 1998 and served as New Zealand's ambassador to the United States from 1998 to 2002.

"To those who worked alongside him, he was a principled and formidable colleague. To his political opponents, he was a worthy adversary who never allowed disagreement to become personal," New Zealand Prime Minister Christopher Luxon said in a statement following his death.

During his time in government, Bolger ushered in the Mixed Member Proportional electoral system that New Zealand still uses today.

His government also concluded the first of the settlements or compensation payments between New Zealand Maori tribes and the government for the impact of colonisation.

Tukoroirangi Morgan, chair of the Waikato Tainui iwi or tribe, said Bolger leaves a legacy in the settlement space that will remain unsurpassed.

“Jim modernised the whole process of reconciliation in an effort to bring Aotearoa-New Zealand closer together to reflect a more contemporary reality of our nation," said Morgan.

Bolger was a committed republican, seeking New Zealand's shift from constitutional monarchy of Britain, and did not take a knighthood after he left politics. Instead he was made a member of New Zealand's highest order, the Order of New Zealand.