General Motors is to spend US$88m at its Lansing Grand River Cadillac assembly plant in Michigan on equipment and tooling for an unspecified new model.

GM won't comment on model specifics but US magazine Motor Trend is picking either the 'ATS' - a new small Caddy aimed at BMW's 3 series - plus, possibly, the larger 'XTS', replacing current DTS and STS models, or additional ATS variants such as a coupe.

"Employees at Lansing Grand River have earned this investment through the high quality of their work and the flexible manufacturing that has been a hallmark of this plant since it opened in 2001," said GM manufacturing manager Gerald Johnson in a statement.

The $88m is part of $2bn in US manufacturing investment that GM announced on 10 May. The money and an estimated 4,000 new and retained jobs are spread across 17 factories in eight states.

Lansing Grand River Assembly currently employs 971 hourly and salaried workers.