Holding company RHJ International posted a sharply wider full-year loss and a 43 percent fall in the value of its portfolio, sparking fresh doubts about its bid for General Motors' Opel unit.

Stock in the Belgian player -- which GM has named as a rival Opel suitor to Canada's Magna -- fell 14.3 percent at the open and was down 7.5 percent at 4.21 euros ($5.92) per share at 0815 GMT, after reporting earnings late on Tuesday in which its loss more than doubled to 1 billion euros.

RHJ can't acquire a majority stake or a large minority in Opel, because they simply don't have the cash -- RHJ doesn't even come close, KBC Securities analyst Tom Simonts told Reuters on Wednesday.

He added RHJ may have an eye to taking a small stake in Opel, which he said could help them support their automotive subsidiaries, such as Belgian auto parts maker Honsel International.

RHJ said it had 447.7 million euros available for investment as of end-March while, in contrast, rival bidders Magna and Russian partner Sberbank Rossi (SBER03.MM) planned, as of end-May, to inject between 500 and 700 million euros into Opel, if the deal goes through.

RHJ's statement did not address its Opel bid, which General Motors has confirmed but which RHJ has never commented on, though it did cite the floundering sector as a reason for the sharply wider loss.

The company's automotive assets suffered the effects of severe and rapid volume declines, RHJ said.

RHJ said in its statement it would likely focus on financial buys. Our cash position continues to be a key strength as we review new investment opportunities and possible expansion into new strategic areas including, but not limited to, financial services in Europe, Chief Executive Leonhard Fischer said.

Other market-watchers suggested that RHJ, which has been hankering for a bank buy for some time, may be using the Opel speculation to boost its profile with German leaders and ease its path towards an eventual purchase of a politically sensitive Landesbank.

RHJ's holdings include automotive and auto parts firms Asahi Tec, Honsel International, Niles and U-Shin, along with media group Columbia Music, hospitality firm Phoenix Resort and nutrition products group Shaklee Global.

It said as of March 31, 2009, its total portfolio was worth 912 million euros, 43 percent lower than the 1.6 million euros it was worth last year.

RHJ said it booked a loss for the year of 1 billion euros, more than twice the 467 million euro loss it booked last year. It reported consolidated impairment charges of 939.7 million euros. ($1=.7077 Euro)

(Reporting by Anne Jolis; editing by Simon Jessop)