The board of directors of United Rentals Inc has authorised the start of a process to explore "strategic alternatives" to maximise shareholder value, including a possible sale of the company.

UBS Investment Bank and Credit Suisse have been retained as financial advisers.

United Rentals said in a statement it would not disclose further developments until the board had completed its evaluation or approved a specific transaction.

United Rentals claims to be the world's largest equipment rental company. It has an integrated network of almost 700 rental locations in 48 US states, 10 Canadian provinces and in Mexico. Its 12,000 employees serve construction and industrial customers, utilities, municipalities, homeowners and others.

Charles K Wessendorf, United Rentals' vice president for investor relations, said almost 20 per cent of the company's rental fleet by value consisted of forklifts and materials handling equipment. The total value of United Rentals' fleet is USD3.9 billion.

Aerial work platforms are the biggest equipment category in the fleet.

Wessendorf said there were plans to grow the forklift rental fleet "consistent with the growth rental capital" in its outlook.

"The total growth rental capital for our rental fleet in 2007 is about USD125 million," he said.

Company CEO Wayland R Hicks, 64, will retire at the annual shareholders' meeting in June but will continue as board vice-chairman. Michael J Kneeland, United Rentals' executive vice president and chief operating officer, succeeds him.