The US Teachers Insurance and Annuity Association has extended the contract of its chief executive by an extra year while the country's $406bn (€313bn) provider of pensions to professors, doctors and scientists continues to search for a successor.

The Teachers Insurance and Annuity Association board of trustees today has extended the employment agreement of Herbert Allison, chief executive, president and chairman. His contract was set to expire in November this year and has been extended to the end of 2008.