Malaysia's ruling party has agreed a series of internal voting reforms in a bid to counter charges of widespread corruption and revive public support.

The move comes after the United Malays National Organisation (Umno) suffered major losses in last year's national and state elections.

Prime Minister Najib Razak had personally pushed through the reforms, warning his party that without changes to make it more transparent and democratic it could be defeated in the next elections.

"Umno needs to open up and improve," he told delegates at the party's annual meeting in Kuala Lumpur on Thursday.

"The people have sent a clear message to us. We are aware and we repent."

The reforms will vastly increase the number of Umno members who will be able to vote in party elections, and allow more party members to contest top jobs.

The changes will slash the influence of traditional party warlords who have benefited from Umno's previous culture of patronage, analysts say.

"This move is historic because no other leader, especially one in power, has been willing to change the system that placed them in power in the first place," Hishamuddin Hussein, Umno's vice-president and Najib's cousin, told party members.