Volkswagen , the world's second-largest carmaker, posted an unexpected decline in fourth-quarter operating profit as inventories of unsold vehicles nearly doubled, ending an otherwise bumper year on a downbeat note.

Based on preliminary full-year results published on Friday, quarterly operating profit slipped 0.9 percent to 2.29 billion euros ($3.05 billion), just missing forecasts for a slight increase to 2.38 billion.

The results come after Europe's number two carmaker PSA Peugeot Citroen

pledged to sell key assets and cut more costs after its automotive business swung to an operating loss.

The French rival is now in talks with General Motors' loss-making German carmaker Opel , because it has a high exposure to the shrinking European market, unlike Volkswagen.

VW is not entirely immune to the economic downturn in its home region, though, despite its strong market position in the relatively dynamic economies of Asia and Latin America.

Car production at VW outstripped deliveries by nearly 100,000 in the final quarter, creating a stock of unsold vehicles that was nearly twice as big as the number of cars built in the first nine months.

The group's cash pile, needed to fund the possible takeover of Porsche's

sports car business this year, shrank to 17 billion euros at the end of December from over 21 billion three months earlier.

It's not bad at all though, considering they splashed out some 7 billion to buy shares in MAN and increased their investments due to the all new Up! minicar and upcoming Audi A3, said Silvia Quandt analyst Albrecht Denninghoff.

After this amazing rally at the start of the year, though, upside potential is dwindling, so adding to your (investment) position now is not as great an idea as it was two weeks ago, he said.

Shares in Volkswagen edged 0.4 percent lower to 138.60 euros by 1100 GMT, trailing a European autos sector <.SXAP> that gained 0.6 percent.

Preferred stockholders will receive a payout of 3.06 euros per share, which was below the average estimate of 3.16 euros.

Volkswagen is expected to publish detailed results for the full year and an outlook for 2012 at its annual news conference on March 12. ($1 = 0.7511 euros)

(Editing by Chris Wickham)