CHICAGO (Reuters) - The MacArthur Foundation, which surprises dozens of individuals each year with its "genius" grants, announced on Thursday awards of up to $500,000 to nonprofit groups it said are doing inspirational work.

Among the recipients of its first-time "creativity" awards were a Chicago organization that promotes affordable housing, a Nigerian group that holds police accountable and an advocacy group in Mexico for human rights and health care.

Criteria for the no-strings-attached grants are that the groups be small nonprofits, with annual budgets of no more than $2.5 million, the Chicago-based charity said.

"These awards recognize nine extraordinary organizations and, we hope, allow them to unleash their inspiration and impact on a larger scale in the future," MacArthur Foundation president Jonathan Fanton said.

The grants included $350,000 to the Chicago Rehab Network for its housing work, $300,000 to the police watchdog group CLEEN Foundation in Lagos, Nigeria, and $500,000 to Fundar, the human rights-health care organization in Mexico City.

Other awards were $250,000 to the Moscow-based Independent Council of Legal Expertise, which works to improve Russia's legal system and helps journalists; $500,000 to Knowledge Ecology International, a group that breaks down intellectual property barriers to make medicines available in developing countries; $400,000 to North Lawndale Employment Network in Chicago, which helps people released from prison; $325,000 to the Peruvian Society for Environmental Law, which helps conserve the nation's biodiversity; $500,000 to RealBenefits in Boston, which assists poor people in obtaining government benefits; and $300,000 to SEARCH, a group in Maharashtra, India, that provides health care to 100,000 people in 86 villages.