MG Rover's controversial £16.5m trust for directors is likely to pay out pensions worth three times as much as the figure quoted by company chairman John Towers, a pension expert claimed last night.

Mr Towers said this week that the fund would provide a pension of £80,000-£85,000 a year for the directors, compared to typical senior car executive pensions of about £150,000.

When the Guardian asked pension expert Tom McPhail of annuity provider Hargreaves Lansdown to crunch the figures, he claimed Mr Towers is in line to pick up a pension of up to £245,000 a year.

If so, the payout will put the Midlands businessman, who bought the carmaker four years ago with three other directors for £10, in line for a pension equal to that enjoyed by long-serving bosses of FTSE 100 companies.

The figure is based on Mr Towers, now 56, retiring at 60 with a one-fifth share of the total pension pot. It uses standard industry assumptions about investment growth, charges, and annuity rates.

The bumper payouts for directors are in contrast to the position of production line workers at the company, who are staring at a deficit in the main pension scheme.

The last reported accounts show a shortfall of £67.6m in the employees' pension fund.

Mr McPhail said: "I think it is highly questionable for Mr Towers to be complaining about the paucity of his own pension entitlement, when the members [of the main scheme] are not currently enjoying adequate security for their own benefits."

The directors' pension fund was set up in 2002, with a £12.9m initial payment, topped up the following year with a further £3.6m.

This week Mr Towers said that cash injections into the fund have now ceased.

The payments were criticised by Jim O'Donnell, the UK managing director of BMW, who said earlier this month that it was a "disgrace" that the Rover board pay themselves more than the board of BMW, when pensions are included. "It is the unacceptable face of capitalism," he said.