March 15 (Reuters) - The National Association of Realtors said on Friday it has resolved a slew of litigation accusing the trade group and brokerages of conspiring to keep real estate commissions artificially high nationwide.

Under the settlement, the realtor group would pay $418 million over about four years.

The accord also resolves claims against more than 1 million members, state and local realtor associations, and most smaller brokerages. Court approval is required.

As part of the settlement, the realtor group also agreed starting in mid-July to prohibit offers of broker compensation on its Multiple Listing Service, and require participants in that service to enter written agreements with buyers.

Home buyers had sued the realtor group and many brokerages over the longstanding industry practice of having home sellers pay the combined 5% to 6% commissions for their own agents and for buyers' agents.

Critics say commissions should be lower, and sellers should be able to list homes on various databases without paying buyers' agents.

In October, a jury in Kansas City, Missouri ordered the National Association of Realtors and several brokerages to pay $1.78 billion, which a judge could have tripled, in an antitrust case over the commissions.

(Reporting by Jonathan Stempel in New York Editing by Matthew Lewis)